Re: Stumped on what CC/Mod is causing game to crash?

It's possible for a save to be corrupted, but if it's not crashing with CC and is crashing with some other CC, it seems more likely to be the CC. You can do testing on a new save, though.

Crashing even a few hours into gameplay is also not normal, though.

Okay, for the build CC, you can test in a couple of methods: by creator or by function. If you already organize your CC by creator, that's probably the easiest method. If you don't have it organized, though, you could either organize by creator (with an "everyone else" for creators who don't put their name in the file name) or by function. If you organize by function, I'd suggest first testing batches of appliances, activity objects, doors, fences and gates, and seating.

You might also have duplicates, which while not likely to cause crashing, isn't going to help. MC Command Center and Better Exceptions both have ways to help you identify and get rid of duplicates.

Sims 4 Studio does have some batch functions that you might want to run on CC in case you got older content that was never updated for particular patches.