methodunderg, Full Edition was released today. Yes, I do and textures from data\maps\generic folder (only about the trees - them too listed in ide's in this folder - I can not say exactly).
I hope so. Maybe even work with nature is more interesting. A have a lot my own nature textures.
The cities are the hardest. I bet the countryside will be much easier.
Well, judging by what I've read, you don't have much of SF left. LV is a little smaller than LS and SF. The country side, many textures repeat so I think it may go by faster. As for the underwater portion, I bet that could be done fast too. This is unless your planning on making the textures be less repetitive.
The desert is part of the country, so LV itself is only the city.