I have a priest alt at 90, surprise.
In case you are not realizing it, everything I said was purely for shadow. The whole discussion is about shadow priests, not about how to completely screw over the priest class :/
Tell me, how would a 1min cd mass dispel for shadow change stuff for PvE? The healers may need to work a little bit harder, but in case you already have a priest healer, you won't be needing a shadow to dispel.
As for burst, does it matter it's easily counterable? Since I main a warlock, let's look it from my side. If my chaos bolt would hit for 300k, would the burst be overpowered? According to your logic, it's fine because it's easy to counter.
You can't always counter something in time because of cc, los, whatever, so just because it's easy to counter it doesn't mean it should be OP if not countered.
As for hybrid healing and shielding, yes, it has had several changes, nonetheless, it's too strong. And iirc the last change was a buff, not a nerf....
As for the offensive dispel, I don't mind classes having it, but dispel magic is way to cheap. What is it, 2.4% of base mana? A purge is like 16.5% and spellsteal about 21-22%... Due the ridiculous low cost it's a no skill button, you just mash it till everything is gone without having to worry about mana. Imo, that needs a change.
I understand you are a priest and don't want changes, but sometimes it's just necessary. I'm not saying priests need to get nerfed to the ground, just toned down. Some things look ridiculous, but if you think twice, you realize it won't change too much and your spec will remain viable.