Haha, don't feel too bad about that finished map to post ratio; or conversely, maybe I need to feel worse about mine! I'm at roughly 1/250
Looks great, hohum. Also, about #3 ... you may want to check out RobA's file-linked layers script, it helps immensely with compositing all of those separate files together. When I work on each piece, I just save a copy of it as a .png and then have one composite file where all of those pngs are there as file-linked layers. It's made it much easier to work with.