Sorry OP, and other guys!
My DPS rotation said Psychic Scream instead of MIND BLAST! It was not based on what a Raid boss would tell me to do... re: dot slots... and indeed SWP is single viable dot unless in a group of SM LOKs (and how often does that happen... sigh.)
Also PVP: was usually NOT in Shadow form in Arathi or WSG... some SPriests actually give up SHADOW FORM and finagle their points into IMPROVED RENEW,or DIVINE SPIRIT.
MANA: I guess I am asking here; are not the beneficial mana reduction skills fairly early in the DISC tree? I for one as a shadow/disc priest Healing a < DM N instance, NEVER needed to drink as often as a Mage/Shammy... but i had a "Healer' set of gear... which REALLY is the difference in these dungeons... IMHO.
So... why did GOD invent Major Mans Potions? so you can drink them! (f-you Warlocks you can bandage.)
Lastly: "Drain" made a comment about wands, that I kinda dismissed. Wands are HUGE, lvl 1-20 for a priest. But then again wands are HUGE for locks and mages 1-20 as well. Point is KEEP your wands updated all the time.
Hope to see you all in game!
ps
If OP rolls DWARF priest... please level holy only and favor gear with Agility/Strength...