Yes, it can be run on a normal PC. Im doing that right now. My pc is running 24/7 right now. I think I'll switch to a server in the near future. The faster the CPU (plus if I implemented multithreading) the better the estimation gets.
And yes, it's compatible with any gameplay combination. It all depends on the underlying simulation. If it's implemented there correctly, the MCTS works with it. That's the advantage of this approach compared to a statistical one. With a statistical approach you need lots of data and if the devs add more restrictive rulesets the statistical approach will get less and less effective. For now it's still really good. See top 100 for that.
Regarding DEC%, I wiped mine out last season. But this season I'll play a bit slower as I haven't seen a huge advantage in regards of rank. Aicu was running high freq (15 sec between matches) and aicu-chan hourly. There was a more stable gain to aicu-chans ranking. So I set aicu back to hourly as well. And see how it plays out this season.
I don't think you are stupid, you just set your sight on other topics. I sometimes forget that what I've learned is not common knowledge. I really need to consider that when writing posts and explain things better :)