Something seems to have been improved marginally around the AL/M&G mark as far as performance and loading goes, if that helps.

Jesus Christ. I bet people don't have to shit in your Shreddies. I bet you have a carton of shit that you pour on them every day yourself.

Pretty sure the issue is that developer videos represent the only time the developers have played the game. Perhaps they imagine the yoohooing is a feature someone else implemented for reasons that escape them.
You can't tell me someone playtested FreeTime for more than five minutes and called it release-worthy. It wouldn't have gone gold the way it did if someone had actually played the release candidate.

-bursts into tears-

Yeah, I figured you'd bring that up. The insanity of toddlers and pets is probably the only dark spot I've left in my game after all the cheats and FFS hacks. Screaming babies and pets eating couches serve to remind me of how lucky I am to not have Sims obsessing over turning off their loved ones' computers, bawling about route failures, getting creepy phone calls when they watch television or serve dinner, and waking up at two in the morning to stare out the window at the rain. A little chaos I can live with, but only when it's chaos the idiots who programmed the game intended; the chaos resulting from their ineptitude, the chaos of a game that isn't working correctly, that's not something I'm okay with. Thankfully you've fixed pretty much every dealbreaking example of that already.
It certainly is bizarre that the pets have their shit together when the Sims do not. Like you said, you can train the pets not to do their disruptive behaviours, but the disruptive behaviour of Sims is probably an unintentional side-effect of lousy/lazy programmers. When pets scratch the couch, it's because they haven't been trained not to; when Sims turn on the television in someone's bedroom while they're sleeping or scream at you when they can't autonomously cook a single plate of food because you've directed someone to cook for the entire family, it's because they have no spatial awareness and their code doesn't allow for any sort of self-sufficient undisruptive SENTIENT existence.

Figures. You train the pets to piss in a box, and you train the Sims to piss in a toilet... the pets remember, the Sims forget. I guess it's kind of telling that Sims display the exact same urinary behaviour whether or not they get the 'training.'
Then again, since you don't control the animals, it's not so irritating that they rush off to the box without your input... if the Sims exhibited similar behaviour I'm not sure I'd be impressed. They're obsessed with their pee enough as it is.
Their AI really is atrocious though... without Awesomeware, they can get caught in energy/hunger failure loops where they slam their faces into their dinner over and over until they die of a brain hemorrhage. The hidden ninth motive is the strongest of all - the need to complain endlessly in order to waste time that could be better spent correcting the problem.

[edited to remove myself from the recursive "which is funny" loop]

I feel like Pets is probably the least important expansion... which is funny, because Unleashed's little neighbourhood renovation made it one of the only expansions the original game sported that didn't seem like a worthless skin and object pack. I absolutely loved watching my first cat in Pets... and within a few days, I was having my Sims pawn their animals off on the adoption agency because they just had no lasting appeal. I still like having the options there, but considering how little the expansion added beyond the aminals it's probably pulling the least weight of the bunch.

Do they need to be the exact same stairs, or are physically identical, cosmetically different ones acceptable?

I suspected at least one or two of those elements would end up being a feature-carried-forward. I've had all the expansions for so long that I've nearly forgotten which one does what.

Depending on how OCD you are, they could ALL be must-haves for various reasons. All the main themes aside, I tried to look at them in terms of "How will this directly effect my gameplay?" when I was pondering what to buy.
I can't part with BV because of the sheer joy of WALKING SOMEWHERE without waiting for a taxi or dealing with the tedium surrounding personal vehicles... the vacation elements leave me cold, really.
Mansion and Garden added the setquartertileplacement cheat, which is easily the most pathetic reason to want an expansion... but man, my anal retentive mind was not pleased with never really knowing if something was properly centred through snapobjectstogrid false.
FreeTime and the dual-core sims, obviously... but man was that ever borked to the point of unplayability before the swath of bug fixes Pescado released. Who in their RIGHT MIND thought the hobby bosses should call you every time you eat, watch television, or take a dump?
Apartment Life added the ability to raise or lower wall decorations IIRC, which is another tiny little nitpicky thing that either is a must-have or makes you go "Seriously? Forty bucks?" Reputation... well... I'm a sucker for anything that adds to the already horrifically cluttered UI of each Sim. The more personalized you can make a Sim, the happier I am.
Not sure which of the last bunch added the roof slope adjuster, but that's also awesome.
Another Aspiration in NL, Influence in University, hairstyle-per-outfit in Seasons... I can never have enough tiny tweaks. Witches, apartments, spontaneous combustion and creepy hobby stalkers I could have done without.
The one single thing they've gotten better at seems to be adding additional "Oh by the way" things that don't directly correlate to the main theme. Unfortunately they've also apparently decided to make beta testers of their customers... FT and AL were just unacceptable as retail products. MATYware makes them a lot more entertaining.

Stupid ex-NPCs from College always seem to use their "Special" outfit ahead of any others when encountered while playing a different family... and there's no way to change that "Special" outfit in the game, as far as I know.
Probably one of the most irritating bugs that never got fixed.

Funny how quickly it goes from "Oh well I'll install this one FFS hack that fixes something that annoys me" to "I'll download them all but leave out the ones I don't like" to "I won't even try to play the new EP until Pescado's updated all the old hacks and fired off a dozen new ones."

I think this is the point where you have to admit your multi-million dollar entertainment franchise has failed. Except that it hasn't... the BBS is full of people angrily shouting down bug reports, saying "You have to take it with a grain of salt" and implying the bug reporters are either whiny or stupid. I always go there with the intent of enjoying a good argument, and I always close the window five minutes later shaking with rage.

Next time I want to buy an EA game I'll just donate the damn money here instead. At least that way it's going to someone whose stuff always works, who fixes it when it doesn't, and who supports it until it becomes completely outdated.

I use Excel to map houses, as I use Excel at work. There's some strange urge for self-punishment that drives people to use Office and Office-related products.

Access?

MICROSOFT Access?

You must be a masochist.

 I don't like that one. Every new release it gets buggier and buggier, the search option is borked, the creator doesn't support it and it's increasingly incompatible with new hardware. Half the time the data gets corrupted and I swear it's always overwriting my old data without asking.

There's also the old-fashioned non-awesome way of just re-rolling the Create a Family babymaker a few times to clear it up (assuming it's just the stuck genetics effect and not something weirder.)

The custom content dialog at startup will be reset to "disable" and the program will crash if it is set to "enable." EA tech support indicates that this is working as intended.

We have a winner!

Yeah, that's how it works... and then you can Merge them back into the household with all their money.

Yes, it's easy to 'just not do the stupid cheaty thing,' but I'm always intensely uncomfortable when the game has, programmed into its normal gameplay, things so easily exploited that they must have noticed it when they implemented them. I wish they'd leave stuff that borked for console commands, so you know you're cheating when you do it.

I bet that, at least, having two items on the wall will cause one to stick and become undeletable, conferring this honour on the wall as well.

I have the awful cheap photocopy-quality pack versions; they're good for a laugh on the can, and not much else.

Christ, are they serious? The 20 000 crap was enough of an exploit, particularly with the Merge Households tool.

Kinda figured it would be, based on precedent... was really just shamelessly padding the post.

Playable witch Sims in a multi-playable-family apartment will, when one of the other families is loaded, be capable of autonomously casting their entire range of spells. All the Cast Spell interactions will advertise higher than any other interaction in the game, as is the trend with new EPs. Apartments with evil witches will, therefore, burn down in less than a day thanks to fireball spam.
Witches encountered on community lots will also cast their spells autonomously, resulting in Mrs. Crumplebottom becoming a toad and the game becoming unplayable.
The iconic witch NPC characters will harass you with telephone spam every time you perform a witch-related action.
Lap dogs will become stuck in laps. Sims holding lap dogs will not be able to leave their chairs, ever again.
"Witches" will be added as a turn on / turn off. The "AL is offensive to Wiccans" thread will immediately revive.
All new social interactions will invoke crush / love and jealousy reactions, with the exception of romantic interactions.
If an adult is swinging a child and becomes queuestomped, the child will disappear, become unselectable, and lose all autonomy. The Social Worker will come a few hours later to remove all household children because of 'neglect.'

He does. He's a Mr. Big. So many skills and so much money that they're instaboring, and with a big nose to boot.