I asked glu about this very topic. They said they select players once in awhile who they feel are very active in game and in forums like these. So keep that up and hopefully they see that.
Yes your prime players can evolve. They take more evo than regular players to evolve though. I would try to level them up as much as possible. Depends on what your looking for. Are you wanting more of a challenge? If so moving up will give you that. Having your prime players capped will give a better chance against teams…