A, B and C are all ok. Really just decide whether you want to be more the defensive buffer / healer that keeps the party alive (then go for A) or if you want to have good offensive buffing (B/C).
Regarding C I want to say that right now, you can go with 1/5 Stone Skin because block increases with SPR*4 so if you are pure SPR build the bonus from the skill points is neglectable. But on kToS the skill was heavily nerfed to only give SPR/2 additional block, if we get that update too you will probably regret only having 1/5 Stone Skin. However, you might as well just use a skill reset potions later when the nerf comes.
And yes, I would not learn Incineration at all, it’s usually recommended for INT-based Chaplain, but for SPR-based Chaplain it’s not that good. You can still get it because the only benefit from dropping it and beak mask is that you can put higher levels into Fumigate (3/5) and Pandemic (2/5).
…or you could just save up those 3 skill points and wait for 8th rank to be released.