Yes, it is a free roam game where you roam around killing animals or humans. It also has online modes which is free roam (with other players) and competitive modes
No, but there are small arenas where you fight.
yes you can everything.
I don't think Red Dead Revolver is, but Red Dead Redemption is.
you do not level up on single-player free roam on Red Dead Redemption.
Yes and you get to improve on your profile.
only if u have XboxLIVE
Just go onto multiplayer and join a free roam session.
No you can not
Fight gangs
You find them all around the map
You can hunt, but you can't sell as there are no vendor npcs.
Yes and you don't need red dead redemption to play
Go into multiplayer free roam press select then go to undead