Basically, each method of chatting seems to have different tiers, with more interactions available with each successive tier. In the upper left it says what the person is currently thinking of the conversation. Friendly chatting starts with them "thinking [sim name] is okay." Next after that is thinking you are sociable and thinking you are friendly (can't remember which comes first).
Flirting starts with "[sim name] is flirty", then followed by "is very alluring", and finally, "is extremely irresistible". From what I've seen, going steady only shows up with that very last stage, and I'm assuming marriage is the same. And you get to the next stage by doing the interactions in that grouping till it gets up there. Yes this means you usually can't just walk up to someone and do the woohoo interaction for example (unless you have specific traits blah blah blah).
I can confirm part of this after struggling with the Goths. You can't just hop the married couple in bed and expect to try for baby even though the actions are in the menu. Woe betide you if you try. I knocked quite a bit off their relationship and had to work them back up to simply kissing. If we have to go through this rigamarole every time we want kids, it's a big do not want for me.
I've not played extensively, but I can say that there is something about the game's graphics that make me think of Fisher Price. Spore gave me the same feeling - kids would probably like it.
I really love how the landscaping looks. The scenery is pretty and I love that the sims' eyes have a wet look to them along with a reflective shine (for lack of a better word) that keeps its position when your sim moves his/her eyes around. I'll admit that the open neighborhood is niftier than I thought, but I don't know if 3 will last for me beyond the new game novelty.
I'm already wanting more patterned swatches for CaST because a lot of what's included aren't to my taste and I want hair that doesn't look like it's either vinyl or matted animal fur. Creating a truly unique sim is somewhat challenging and getting away from pudgy faces is proving damn near impossible. I thought I had one until I got my sim in game and looked at her from a distance. Overall I suppose I'm enjoying it, but as I said before it has the novelty factor going for it.
Oh, and has anyone noticed that choosing what to paint for a 'still life' is counterintuitive? Whichever direction I move my mouse, the 'frame' goes the opposite way. Combine it with hypersensitive scrolling and I got a good five minutes of
frustration fun. I had Agnes Crumplebottom go to start a still life at 7am, and couldn't get the picture I wanted by the time her carpool arrived an hour later.