So this is an idea I got about a supporting cleric that obviously is not ment for solo play.
Cleric(c2)>Priest(c3)>Devdirby(c1)>Plague Doctor(c1)
Mostly ment to give out diffrent buffs and heals, with more focus on defense.
As for stats (for each 10 lvls):
6 spr, 3 int, 1 con
Thoughts?
What is bad and what is good? Why?
I’m not sure about the Plague Doctor portion, however, the priest bit could definitely use some work.
Monstrance doesn’t increase the DEX it gives based on level so only one point is recommended.
Aspersion is definitely not worth getting to a high level, physical defense is surprisingly weak. Although I’m not really comfortable saying it’s useless… I don’t think it’s worth the points unless your going Chaplain.
You could take some points out of Mass Heal for something like Revive/Resurrection however this is debatable as the idea is that it scales with both SPR/INT.
You should have a bunch of skill points now, what I recommend is get Sacrament because it gives another hit and blessing applies to both. (If you have +50 damage from blessing it becomes +100, effectively)
It should look something like this:
And if you didn’t really want sacrament then put the points in Blessing/Revive
Also I’m not so sure about your stat point distribution, the only thing that scales (Solely) with INT is Heal/Cure.
As for the Dievdirby/Plague Doctor, someone else is gonna have to answer that, as I’ve got no clue. Also have you considered Pardoner? They can increase Magic Def which is huge in party play since most Warriors have 0.
Anyways, this is based on my experience from iCBT2.
I went: Cleric-Priest-Priest-Priest-Monk
Additionally, leveling solo is not recommended as this is obviously a support build. I.E. Find some friends you’re going to do any build without attack skills… Which I just realized you mentioned in the beginning of your post, but whatever I’m leaving it in. 
Everything, full support clerics are a incredibly poor option in comparison to other cleric builds.
You got no defensive skills worth their salt, just healing and a bit of utility. Meaning your allies will die because prevention is far more effective.
Ow and most routes with proper dmg prevention still get solid dmg and better utility.
They’re also a pain in the arse to lvl.
Thanks for the input!
You have some solid points inn your arguments and I see what you mean. I have not played the game myself as of now and can just theorise…
About the Doctor: it´s used mostly for cleansing debuffs… not sure how needed this is tho.
And Dievdirby might be swapped for Pardoner as they both are interesting in my eyes and bring some utility. It´s basicly skill cooldown vs. mgk def.
I think you should consider Krivis over Diev because of Zalcai. That way your SPR will be even more effective(Crits yo).
What could be changed:
Get Fade lv1. It’s a very usefull skill for both PvE and PvP.
Keep blessing lv5, the dmg scaling is pretty poor and you’ll prob only use it up untill the 200s.
Max Resurrection.
Get Incineration lv5 over Fumigate, you shouldn’t skip on skills that do great in party play and one of those is Incinerate(bc it scales with seconds by the amount of debuffs the enemy has).
The def reduction of Monstrance is pretty poor and the cast time increases with lvls so, I’d suggest it lv5(max) and putting those 3 points into Revive.