It is also awesome defensively since Aura of Flaming death soaks up incoming damage with damage returned. Its like having a monster fire shield and stoneskin spell all in one
Or chain together 3 bolt of glory spells in a sequencer for some major damage on demons, etc. Holy Smite does 1d4 damage per level ( with a save for half ). At higher levels this can generate extreme damage on groups of evil NPC's when sequenced. There are alot of possibilities here.
Just keep in mind the tradeoff is slower leveling so it make take you a bit longer to take advantage of the higher level spells.
Im not sure what level you get more than one level 7 priest spell. Consult the spell tables in the ToB manual's appendix. Or, when I get home, Ill look it up and post it for you.
If your still unsure, you can always expirement with Aerie since she is a mage/cleric.