Only some "Spetznatz", no "regulars". And for gods sake no, they won't be just retextured CSAT.

My Ravage got a little bit out of hand 
  Sosnovka. It's one of those awesome moments, and I don't really have an explanation of how all of this happened. I encountered one stuck T55 and then one BMP1, then another BMP appeared behind me shooting me in the back (ERA saved my ass) and I had to bail out fast before it fires an ATGM and I had my rpg7 ready, blasted it, and THEN I got shot twice by a squad coming from the forest, but my vest saved me. Total chaos. BRDM came along to join the fun but I planted explosives just to damage it really good to force crew out so I can get ammo/supplies, destroyed it afterward.

There will be regulars Russians troops ? Basically CSAT infantry but with Russians, voices and skins, and AK-12 variants in a sub-faction like the Scimitar Regiment. 

I'm afraid not. 😕 Changing time in MP will always causes issues, unless you do it for everyone server-side. Although it wouldn't pose any problem for a lone player in MP, it's impossible to add that feature in a manner that would fit other configurations.   If you need, I can write a small script for you to use on your server.

Using BB, or intersects, point cloud with array subtraction and such. Mainly looking for ideas how to optimize this as much as possible if you want to run this across all terrain objects