1. Sure, reskins are allowed. I am putting together a repainting template package and will release with the next site update.
2. In short, I generally disfavor alpha parts. I will however be releasing a couple of 'plain jane' versions to boost the painters; otherwise superdetailed units with all the right details will be offered in upcoming Super Sets.
3. Some boys from Altoona may beg to differ:

(That's not to say I won't look forward to your repaint!)
4. The same rules for version 1.0 apply to version 2.0, so the freeware version may be redistrubuted with your skins, as long as credit goes back to Dekosoft Trains.
cheers,
--C.