Factions and Alignment

I like the idea of there being two major factions, with the players belonging to minor factions that become aligned with the two major ones. Given enough minor factions, pvp play balance comes down to reshuffling the minor factions to even up the sides.

A player gains minor faction through completing quests. Quest come in dark and light variations. Dark quests push you towards evil and light quests push you towards good. The two major factions are composed of both light and dark elements. Minor factions may require dark, neutral or light alignment, as would certain abilities.

Respecting Playstyle Boundaries

I think there is a place for more explicit boundaries between playstyle interactions. For example, PVE success should have little to no effect on PVP success and vice versa. This includes equipment, levels, skills, spells and all other attributes.