The age no longer showing up on townies is something that affects a lot of people, if not all. For me,it sometimes does, and it sometimes doesn't. It's not something you can solve, you'll have it again in a new file.
The move in feature not working also seems hit and miss and if you have get to work and played detective, it might have something to do with the crime scenes not being properly cleaned up. That usually clears up if you load the affected house in build mode.
I don't think SLI is really supported but I'm not 100% positive on that.
Crashing could be anything really. Are you using mods/cc ? In what instances does it crash ?
I do agree that games played since release might become wonky with all the stuff added, especially if you use mods and cc.
Anyways, deleting the localthumbcache might help with the choppiness but other than that, I don't think a factory reset will help much in your case and you definitely won't need the files you asked about 🙂