The 'sleep at work' option seems to pop up only when your sim is very very tired, in my experience- at least with Medical and Criminal career.  The first amused me: the idea of the trauma surgeon napping after having been called in on his beeper is interesting, to say the least.

My Criminal track Sim seems to have triggered the sadorandom JAIL JAIL JAIL option.  She's low in the career (level four or five, I think), and it's around twice a week that she gets taken away, no matter what she's doing.  Even if she's just lazing around at work, she goes to the slammer.  I wonder if there's someway to make it pop up less often: my other sim in the track didn't have this much trouble.

Servers are not being cooperative at the moment.

Some traits seem to be able to be 'triggered' for an immediate find-out, too, due to certain social actions.  Ask about work, and you might get 'Workaholic', a flirt can reveal if someone's Unflirty, chating about family will get if someone Hates Children (and I assume the opposite, though I haven't ever gotten that), speaking of Art gets if someone Hates Art, telling a joke can get you the Good Sense of Humor / No Sense of Humor thing... I'm sure there's more, but those are the only one's I've seen.  Still, yeah, besides the super easy Questioning way, it does seem a bit difficult to get traits after 'Get to know' is gone; chat takes forever.

I'm really hating the enforced maternity leave.  At this point, if I have a female Sim who I plan to have children with, I'm just avoiding 'top job' ltw's.  I had a Sim who was at midlevel in the military when she started having kids: her kid was like, two days from child by the time she was working again- and I didn't grow him up early in baby stage.  I need to be better about timing pregnancies.

For music, using a fairly nice stereo, my sims would get a +15 moodlet for the nice tunes.  If I switched it to their favorite station, neither the icon nor the description changed (I think), but the moodlet read +25.  So that does seem to work.  My sims tend to automatically change it to their favorite station, too, if they're left idle in the room for a few moments.

As for the favorite food, I haven't seen it do much.  Sims seem happy eating it, and I've seen 'prepare (someone's) favorite food' wants, but... that's all.  But... someone asked a question back in the thread a bit about being asked to deliver a group meal to someone.  I got that as an opportunity, and invited the Sim over and left him to read while the Sim cooked up (serve full meal or whatever option).  I made around five different dishes and started twitching... but then I made the favorite food of the requesting Sim, and he took that dish happily, but none of the others.

I'm having that issue, too: I've been making various young adults, but many of them start anywhere from one day to a quarter (maybe even a third) in to that lifestage.  I think the first Sim I made was just starting 'young adultness', but even if starting 'new game', others are a bit in to the lifespan.  I'm not exactly sure what to think about that: I would personally call it a bug, but considering the random clones children and 'sims moving out at will' deal, it may be a 'feature'.  Whatever it is, though, I don't like it.

Kids not being able to go musical bugs me.  Fine, if they can't play the guitar- but can't they have a piano?  Or if nothing else, read some books about guitar playing?  Foo.

I am, for the moment, enjoying the jobs- even though my poor medical sim seems to spend the majority of his life at work due to his beeper.  It does make things interesting, though.  My criminal Sim seemed to get arrested every other day or so while at work, though... that was more annoying.

I had a sim that was... Evil, Grumpy, and Mean-spirited or something like that.  (I think I then topped it off with Ambitious and Lucky, but I can't remember- she started spawning clones when I tried another family and I don't feel like actually checking on her.)

Evil options were fairly 'bwhahaha I'm EEEVALLL lolz!' type: my sim would have a FIENDISH shower, sleep FIENDISHLY, eat quick meals FIENDISHly... yadda, yadda.  The only real evil option I saw was the donating to undermine charities thing; all other fiendish options were basically the same.  She also could gloat about her evil masterminding plan, or some such: most other Sims seemed to find it boring.  (Wankers.)  She also would take great glee in declaring other sims her nemesis-es, though.  Ah, now that I'm thinking: it also added a moodlet whenever she saw another Sim suffering (usually by low mood) and made her want to steal candy from her daughter.

Grumpy, I don't even remember what it did.  I think it just made it harder for other Sims to win her over, and she got a bit more enjoyment in complaining... maybe a few more options?  She also tended to throw shit-fits over minor things: lots more 'angry' on her mood meter, and less 'tense' or 'sad'.  More stomping feet and less throwing arms in a sigh when the toilet got clogged and such.

Mean-spirited, I believe, gave some more mocking/insulting options... but mostly, it meant that whenever she saw one of her enemies, she got a happy moodlet.

All three were fun, but I think my favorite is neurotic: the random freak out the Sim has amuses me, as does the 'must check sink' deal.