Mobs in Pagan are lvl 80+. How you survive them? Get a full party, support, healers. Be patient for a good party, the exp inside is great, but it's not an easy sunday farming run.
Quest you can do in Pagan's Temple: "Truth beyond the gate" (allows entry to Pagan's once) and "Through the gate once more" (this one will allow you to open the doors inside).
How to open doors in Pagan ? Use Ante-room keys to open Ante-room doors : target the doors and use the key, beware it may fail. For the Door of Darkness you must use ... (duh!) ... Keys of Darkness. Btw, you can't use the keys in silent move, so be carefull.
Drops in Pagan's Temple :Scroll of Escape to Rune, Ketra, Varka / Scroll of Mystic Empower, Windwalk / Black Treasure Chest, Anteroom Key / Key of Darkness, Lifestones lvl 76 (no - top grade), Einhasad's Holy Water, Elixir of CP (S grade).
I for one really like this area. Mobs 4x, a lot of rooms, good adena and items. Plus you can "visit" (try to kill) Triol's Boss Benom or Queen Shyeed (RB). Good luck ! ^^
Check out this nice Pagan's Temple Wallpaper.