Shit, glad you're OK.

About the depth, that's an odd one. VDNKh is 53 meters underground (just 5 meters less than the deepest one in London IIRC), but two of the stations making up Polis are 12 (Lenin's Library) and 8 (Aleksandrovsky Sad) meters deep and people seem just fine there.

London may lead to some problems weapons-wise, though it would leave room for a lot of metro-made stuff.

As for animals, There seemes to be a lot of foxes there even deeper in the city, though I've only been there twice.