Oh, I don't know. It is pretty easy to get up there. This guide will get you close, My current load (below) is loosely based on this guide and is pushing around 70K strings. I don't feel that it is too ridiculous.
I don't think anything bad will happen other than snow falling through the roof or maybe some weird transitions when moving in/out of shelter. I've had the everyone goes hostile bug a few times. I don't think its caused by any specific mod. You probably kicked a chicken or something. This usually fixes it: Commit a petty crime (I usually pickpocket a torch off a guard) and then get caught any pay off the bounty. This seems to reset whatever flag causes this.
I thought I would share an album from my current build based on excellent Yash'd up guide. I'm not much of a screen archer. Most of my textures are 1-2K. Be gentle. https://imgur.com/a/hHDKN
I am running CCOR before Yash2 and then just forwarding the conflicting recipes and a few outfit records to a patch. It works for me but may not be what everyone has in mind. If anyone wants the patch let me know.
Make sure you pulled those extras ESPs out of main 3DNPC mod in MO into their own mod, otherwise it will try merge all the assets from 3DNPC which will take forever.