ADDENDUM
-The path from rank 3 onward-
I figured I may as well add this tid-bit on at the end. Once you hit rank 3 you will want to immediately head to Tenet Chapel B1. There are a few quests around that are easy enough and mainly just require you to kill monsters. This place is a dream come for true for Priests since all of the monsters are weak to holy damage and the majority are weak to strike damage. Grab your best upgraded mace (the Maul is the best, easily obtained one I’ve seen for level 40), cast Blessing and Sacrament, and get to work wrecking those faces! Work your way up to 1F and 2F as you go along and you will be 50+ before you know it. There is good loot to be had as well. Just watch out for Gesti on 2F 
Once you have cleaned out the chapel, go make/join a party for the level 50 instance dungeon right outside the entrance. This instance will take you to 65/66 pretty easily. Be sure to get yourself a nice sword and mace and grab the weapon swap attribute from your rank 2 master. You will want to be able to switch between damage types as you move along from here on out.
Once you hit the mid 60s you can continue forging onward through the world. I would say the easiest thing to do at this point is to skip maps and get to Gate Route.Start up the quest chain there and fight your way through the series all the way to the Constructor’s Chapel. You can grind there or go to Gytis Settlement Area in the late 60’s. I suggest saving all EXP cards you get from these quests for the last few levels before the rank 4 advance or for the peak of the EXP curve at 86. Things will generally get easier once you hit rank 4 so I think getting there a little more quickly can be a benefit.
Once you have hit rank 4 or even a little before, you can continue on through to Rukas Plateau, King’s Plateau, Zachariel Crossroads and the Royal Mausoleum. Once you hit 90, spam the instance dungeon at Zachariel Crossroads as much as you can and grind in the Mausoleum. DO NOT USE A SINGLE EXP CARD WHILE YOU CAN RUN AN INSTANCE OR GRIND FOR EASY LEVELS!! You should be able to make your way through the following maps and get to 115 or so without much trouble. Everything is pretty straightforward up to rank 5. Just quest and grind where you can.

I’m glad the information is helpful. I should have covered the other attributes in the wall of text but it slipped my mind. It is a good idea to grab that Heal attribute, yes. Since you do damage with auto-attacks and don’t need to rely on Heal for damage it’s always good to know those tiles aren’t going anywhere in the event you or a party member need them in order to survive.