I really like the PvPvE option. Raw PvP is very, very bad idea. I'm on Legions of Lettow server, and in any circumstance, Imperium just massively outnumbers the Republic.
PvPvE fortress-style combat area is what I always loved and will always love. Of course, it should be that the more fortresses/whatever the faction has, the easier it is for it to lose them. Thus, a balance would find itself easily
Population capped PvP is... interesting... it still doesn't promise balance, and people may not be always able to join because of the cap.
Guild-based makes no sense in Star-wars universe, but that's not the point. I really like it, because it's the source of all epicness. However, it gives less chance for casual players to prove themselves, and be effective.