1. there should be two different channels, not one mixed channel.
2. sort of. blueside is a set of content that was connected to heroes originally, now there's no limit on who can access it. same for redside. 1/2 my characters are villain ATs, most play blueside most of the time (but can switch to redside content in seconds by talking to one npc).
specific example: my brute has never been redside. my defender has done considerable redside content.