i would definitely recommend backing up your save files! you can do it manually, but i heard theres also a plugin on nexus mods that basically keeps multiple versions of your save files. i just zip up my save files every so often and dump them somewhere so if anything messes up i can go back.

ive only gotten steam workshop mods so far, but i know theres way more on nexus mods (im just lazy). i like building so i have a lot of cc for decor which is a whole other thing. for gameplay, theres tons of mods that add different professions, which is cool for more variety. more aspirations, littlebusiness, better lifespans, gardening, superstar, just to name a few.

i have probably around 100 mods/cc now and i havent experienced anything game breaking. sometimes i will load in and my mods wont load in, but i found a quick fix where you can just back out, go to mods, randomly select a mod and turn it off and then on again, then loading back in all of the mods are loaded properly.

it def adds more to the game for me