1.)Yes ,You will get the market back since all my ROMs have market
2.)All my ROMs are pre-rooted
2.)Perseus has some cons .To start with it is ext4 and it's still unstable .Plus it's more of an advanced ROM for guys who will be using clockwork mod since ext needs to be checked every month to ensure proper working .
3.)Try the Arkas Einherjar (which has one bug with sports tracker apps which will be solved soon ) or Arkas Ganymede 3/4 (Closest to stock GB )
4.)If you are on Froyo then use Arkas 0.564 which is the most stable rom .