Areas Question

ok, say i own Nightfall, Prophecies, and Factions. Can my Factions Character venture into prophecies territory, or is he strictly limited to factions territory?

He can venture across.
See http://guildwars.wikia.com/wiki/Chaos_in_Kryta quest for details.
There's quests to go across to all three continents, the wiki summarizes them somewhere, can't think where.