I'm sitting in the emergency room waiting area and I'm bored. So I'm going to write about my priest.
As I suspected, it was fucking slow and rough going initially, as my plan (a melee and offensive spell based battle-priest of Eothas) was sublimely flimsy. But I stuck with him and made some good decisions, so things are actually a lot better now.
1) Unlike most other classes, the priest's class talents are relatively easy to pick through if you know what you want. For example, Aggrandizing Radiance is kind of a no brainer. You get a good boost to your melee and survivability, with a hit to your self-healing ability. You can offset this hit by leveling Second Wind, and also by keeping Durance in your party. Having two priests, by the way, makes your party an absolute terror when it comes to fighting vessels. You will fuck fampyres up the ass.
2) Priests really do have some great offensive spells, especially against vessels and those vulnerable to burn damage. Shining Beacon is absolutely ridiculous against groups in particular, and Iconic Projection does decent freeze damage. Finally, various falling, crushing, and burning pillars, and Barbs of Condemnation, get you covered for crush and pierce damage. About the only area priests are deficient in are Corrode and slashing damage, and raw of course (but who cares).
3) For melee combat, taking the favored priest talent and its associated weapon bonuses is a good idea. I gained +10 accuracy with flails which is nice because one of the earliest unique weapons you can get in the Temple of Eothas is a flail (Gaun's Share). Further, medium armor, taking a shield (and the defensive talent that increases shield deflection, and Superior Deflection which drops a flat bonus to your deflection score) really helps you stay alive.
4) You really don't want to try and be a melee-first fighter, and you can increase your lethality by having at least two other melee fighters ready to tank and do DPS. The dual combo of Eder and Zahua as effective anchors helps you bunch up enemies and really pummel them with AoE attacks. If you are in melee, pop your Radiance for the melee boost and you will do respectable damage in between spells, or as a third/off tank to control the battlefield.
5) I'm looking forward to taking Scion of Flame, and the per-encounter spells I'm taking are all offensive-focused: Barbs, Divine Mark, etc. I am also looking forward to getting a decent morningstar (Daybreak is looking good for its holy priest, insta-kill-spirits LARPery) and depending on how it goes, I might respec out of shields and take the two handed weapon perk.
Overall, a melee priest is quite doable if you're smart and willing to lean into the fire dealing. It is a little tougher if you're going to stand up front with Eder because, say, you'd rather have Kana and his arquebus than Zahua and his lunatic fists. But as a damage dealer, he is comparable to a mage and his spell book is so much fatter. He lacks the crowd control spells of a mage, and the raw elemental damage of a druid. But he holds his own smiting ungodly degenerates, and he is physically the toughest out of all the caster classes with a surprisingly high base deflection. I can recommend giving him a go.