The fact that you have a Steam install doesn't make any difference, and it's not RAM use. (Some worlds use too much memory even on startup, but that's not the case here.) Your hardware looks fine too. One thing that does jump out at me in your dxdiag is that the Nvidia 1050 ti entry is missing some information. I've seen that a couple of times recently, with the same card, and in those cases, a clean install of the GPU driver has fixed the issue. So that might help you too.
First though, just to make sure it's not something simple, try playing in a clean game folder. I just downloaded the world myself (the Seasons version, without the accompanying cc), played around in CAS for a bit, and then placed my sim in town. The game didn't freeze, at least in the few minutes I let the clock run and had a look around, so the issue doesn't appear to be the world itself. But it could be a problem with your game folder, and this is an easy test.
Start by installing just the world, and if it runs smoothly, you can add the included cc if you want it and test again. Be sure to delete your cache files after adding the cc. If it's still working, great—you can copy over the contents of your old game folder to your new one. Let me know if you want instructions; there are a couple of tweaks you need to make to ensure that you don't have duplicate files and TS3 still reads all your custom content.
If you're still getting crashes even in the clean game folder, I'll post instructions for how to do a clean install of your graphics card driver.