It would be realy nice if something similar would exist for gentoo ;) http://dosboxed-games.sandbox.cz/ Old games released as free or open-source, or abadoned games[the owner stoped selling the game, and it is not posible to get it by any legal way].
No, we only support linux-native games in portage.
Not to mention, if the rights weren't explicitly given for copying, you're still breaking the law. It doesn't matter if the copyright holder slit his own wrists with a dull hacksaw, he still retains all rights.