It’s Cleric C2 for mainly PvE and Oracle for mainly PvP, not the other way around.
If you’re full support and mostly PvE, go for Cleric C2, not Oracle. Oracle isn’t that useful in PvE. Counterspell has a long cool down and you need to fight inside the circle. It’ll be amazing if you manage to group mobs and if they’re long to kill, but most of the time it won’t really be useful.
You could also go Krivis, for Daino. I have to say it’s kind of annoying to see Chaplains use all their buffs when they have no Daino… I’ve seen quite a lot of Chrono and Thauma rage on that.
You’ll have all the Priests buffs + Divine Might + PD buffs + Chaplain’s extra two buffs. You’ll need Daino for sure. You can still buy scrolls though, but with your build you’ll have to spam them hard (and can’t use them in PvP if you ever want to do it).
Most people that take Oracle take it for PvP and if they don’t take PD, for the Prophecy skill.
If you go Cleric 2 you don’t need to put 10 points in Safety Zone. No matter what it lasts 20 seconds, the +20 blocks attribute is more than enough, you’ll have a total of 30 blocks for 20 seconds. In most case the Shield will disappear on its own before you run out of blocks.