Some thoughts I have (please others add your input)-
1. Holy needs a good instant cast heal like disc's Penance used to be. Holy Word: Serenity could be this heal if it wasn't so hard to get into Serenity Chakra in a pvp environment. Heal is extremely dicey to even get off and you really don't want to waste time with weak Heal just to get in that Chakra. Like we've been saying in PVE, Chakra needs to be a state that is accesible with just a keybind.
2. Body and Soul needs snare resistance. It is currently way too easy to be snared and have Body and Soul do nothing.
3. Chakra, State of Mind, and Revelations are really funky and hard to use for pvp. Chakra states are hard to get into, can take away Chastise, and it is hard to stay in Chakra state. Definitely need some tidying up there. Again, keybindable Chakra states would help a ton. I may not be able to cast the correct spell to stay in state due to the unpredictable nature of pvp, it is frustrating to go to all of the work of getting in state and then have it drop because you needed to dispel instead of cast Heal needlessly just to stay in state.
4. Mana needs some tweaking. With full spirit gear, it's not terrible, but it could use improving. Something creative like Shadow's Masochism would be nice, so it isn't OP in PVE.
5. Make Inner Will usable somehow. It'd be nice to be the slippery Holy Priest living in Inner Will, but getting caught without Inner Fire up by a melee will be instant death.