I don't let stuff like this bother me. It serves absolutely zero purpose in the end.

The OP is right about the rain but this doesn't bother me as much as before because, first, I don't expect anything anymore from Bethesda in matters of water/rain technology(with the exception of Morrowind's water shader which was the ONLY time Beth was at the lead in water graphics) Thank god the ES community is full of smart and problem-solving modders that will eventually fix these annoying problems that the developers are incapable of doing.

That sounds like a colossal waste of processing resources. I hope it's fixed, but I really couldn't care less personally. There are ways of doing rain that doesn't fall through roofs without the insane processing requirements you seemed to expect.

Well, that's what I meant. The fog effect on the mountains looks cool, no question, but you can see the outlines of everything in the distance (see 6:34). So it doesn't behave like real fog where you are engulfed by fog and can't see anything beyond a certain point. Like on http://www.uh.edu/engines/fog9.jpg picture. In Skyrim you would still see the outlines of whatever is behind the trees. Mountains, other trees etc, no matter how far away they are.