My way of playing is somewhat erratic. Don't think I could ever play a challenge with set rules, but I might try someday anyway. I never have aging turned on, because I don't want the premade townies to die. I get attached easily
Plus, they never procreate to my liking. Normally, I prefer to play a premade sim and try to have them live their set lifestyle - preferably turning everything in town(s) upside down in the process. Oh, and I'm always compulsively snatching the Goth patriarch away from their preset family. It's a tradition by now.
Currently, I'm playing Don Lothario. My project for him is to get him to level 10 in all skills and have him complete all aspirations. He is married to Mortimer Goth for the absurdity of it, and at the moment they live in Myshuno City. Their kids will have to be CAS made for obvious reasons, but this way does work for the family aspirations. I checked at some point. He has got a lot of reward traits by now which is cool and useful as some of them dampen his "natural" conflict-inducing tendencies. And he is a pretty entertaining sim to play - always in a good mood and full of himself no matter how badly skilled he is at what he's doing