Help me get back into Skyrim

[The Man in Black]

I'm dipping my toes back into Skyrim after several years away. I used to be pretty decent at modding (I'm the author of the Immersive Daedra Worship: Temple of Molag Bal mod on here), but I'm rusty AF and don't have the time or energy to spend countless hours anymore. It looks like there's been some advances though that I'm interested in:

 

1) What's the deal with anal collisions? I saw some references that that's a thing now. What mods do I need to get them to work? I use BHUNP, CBPC, and Faster HDT (all of which I probably need to update, since it's been a few years).

2) What's the deal with OStim? That was just starting to take off when I stopped playing, but now I see fuckloads of content for it. What mods do I need to get into that? And is it compatible with SexLab?