It's your build, you make your own rules.
But I'm going to make a Priest character after I finish my ranger, so I'll say what I'll do.
Priests and clerics traditionally use maces, so use a mace (shield optional) not a sword.
If you're going to be a warrior, you could have a point into Rush Attack. I wouldn't use Whirlwind, though.
I would also allow Polymorph, because a lot of Priest skills are single-target debuffs, and so is Polymorph, so it would fit right in. I might allow a single point into Fireball if you choose that as your Farglow skill.
Points into Healing would fit a Priest character just fine. Healing is good for all points of the game, but around level 26-30, you'll want 2 or 3 points into it.
I did a test with a normal character who was at the end of FoV, and I was able to max out EVERY SINGLE Priest skill, plus Lockpick, and still have points left over for other skills, so you can technically afford to take all the priest skills, although a lot are not worth maxing out so you can save more points.
