Only had the time to check out the skills and stats of priest so first correction, you need gloria 2 in order to have basilica 1.
So my suggestions on the priests stats would be to either get base 99 vit/99 int and rest in dex or to get 97 total vit 99 int and rest in dex. The first one is to have a tank of a priest but is pretty vulnerable to Acid demonstration, draw back is the fact that whenever the priests uses a skill, the cast time will the bad and you would really need a necklace under cast to make sure the buffs come out. The second one has a bit less hp but is less vulnerable to AD and buffing is less of a problem with the dex from this one. Question, is there a precise reason for the 23 luck, other then the perfect dodge? Because even with gloria it isn't that good to have that low luck and it is better invested in dex.
For the gear I'd say lose the headphone and get a spiky band with an opera mask or lose the marduck considering you allready can't be silenced and but a gibbet card in for +5 mdef. Unfrozen Saint robe is way better then ares. The rest looks ok and btw I went under the assumption that you only had those gear on the priest and nothing else to change with.

Just saying because I never did the USRC and I didn't check all the rules.
That's it for my suggestions, I'll make more when I get back from the aeroport.