<obligatory "see my Tempest Warpriests" thread self-promotion>
There are two issues with this build concept:
- If you go DEX-based, you're missing out on the DPS bonus from Div Might. You also have to spend at least 18 APs in elf tree for Grace, which limits your other options.
- If you go Undying Court + Valenar for scimitar bonuses, you miss out on the longbow bonuses from Aerenal. Given that you'll have full set of ranged feats from rgr 11+, it seems a pity not to use longbows w/MS+IPS. OTOH, if you go Aerenal, you either miss out on Righteous Weapons with rapiers or have to use the sub-optimal longsword / Sovereign Host option. [Or go Silver Flame for longbow bonuses.] I actually think UC works better on, say, a HE w/rog dilly for some extra SA.