Such an open ended question. Tempting. But it depends on how radical you want to be.
Truth is, there is a lot that can be improved. And a lot that works well as is. Issues with the class that players seem to have a problem with are Inquisition, AoE damage, ramp up and the feel of certain moves such as HoW.
My own thoughts are simple:
Inq needs to be removed or redesigned. It is intended to add needed complexity, but in truth, I don't feel it succeeds. Personally, I'd remove and work the
complexity into the HP system which should be expanded upon. I just have the feeling Blizzard got bored wih reworking the class and left it alone this XPac. No Inq also helps with ramp up.
SoR should be removed or redesigned. I don't think the AoE Seal mechanic works well. The damage component, such as it is, should be added into the various AoE moves to make them feel meatier.
HW (old style - I do like the new 'melee' version Prot has tho), Exorcism and Consecration should be baseline. They add flavour, a provide scope to boost AoE damage and vary the rotation. I'd consider making DS and TV baseline and MELEE abilities (not spells affected by silence) but while I feel such as sytem woudl give the class a very decent baseline toolkit, it removes much of the variance between specs.
The first talent tier should be reworked. PoJ should be baseline, but with an active component - when active, increases speed by X% for Ys. Passive PoJ aspect inactive for Zs afterward and sprint has a X min CD. Give the class some baseline mobility.
DP should be baseline. Give it an ICD or something, but the talent really helps fill out the rotation. A filler move of some sort may still eb helpful to keep the rotation flowing.
I still miss Auras.Don't know why.
Yes. Only I'd call it Zeal and tie it into the melee system instead of Inq.
No. HP, or something like it is needed. It adds complexity, it adds hooks for various abilities. The problem is its currently simpliied nature. At the very least, it neds to mesh into more moves and abilities.
EJL