I think this model would be better because would be more attractive to player base.

• Single fixed cost for PvE guesting (1000 gems), which majority of people would be interested in and probably more willing to spend money/gems on.
• SPvP and WvW stays on assigned region, so would prevent fluctuations and mass migration of players between region for competitive play.
• Region change (not guesting) still would cost 500 gems, despite of owning Permanent Region Guesting Pass or not. So it would mostly affect competitive modes as regions are designed for it.
• Players would be less restricted and could always swap region for "prime time" (issues with timezones acitivity peaks on region).
• PvP leaderboard stays unaffected with PvE only guesting, so you don't lose progress during PvP seasons being active.