I just did my first quest at Raven Rock clearing that mine for the guy that stole the miners pick. It was Hard! I'm at level 33 and the only way I survived was hiding and conjuring Fire Atronaches to wear the DragonPriest down. No way could I have fought him directly. Maybe I should go back to the mainland for a few levels. What level is best for that island?

Dragon priests definitely are not easy at 33. They are typically lvl 50.

The ones on Solstheim are actually level 60, and often uses masks that improves elemental damage, so they are even more dangerous than the ones we meet on the mainland.

It was designed to be hard. It is reccomended you go at about level 20, but that is just the mininum level for the leveled enemies if I'm correct. If you need some better light armor, at level 36, if you read a book called Deathbrand it will start a quest for it. It won't be too hard getting the pieces of all the armor, but finishing the whole thing will be tough.

At high enough levels you will start to not worry about aything

What difficulty do you play on? I went there with characters at about level 20 on expert difficulty and had no major problems really. Solstheim is fairly difficult but not overly so.

I started it at Level 40 and it wasn't so bad, but my Destruction is way high in both fire and shock, I have the Soul Tear shout so I can raise zombies without wasting magic, and I also had Farkas and a conjured Dremora with me to do the melee work. So I guess the best advice I'd give is don't go in alone.

The enemies are much more challenging. I freakin love Solstheim!

Level 33 you say. I don't recall when storm atronachs appear, but it should be around when your conjurations is like 75 right? Try to get Frost/Storm atronachs if you can, they're better than fire ones and can tank more. Also, use sanguis rose if you have for some dremora help. Some resist magic/fire/ice potions wouldnt hurt either and ofc, a healthy stack of health potions.

What are your main abilities? Defeating Dragon Priests with magic can be a serious challenge, as they are resistant to it and destruction is generally very underpowered. Unless you're playing at expert/master/legendary difficulty, I find it a bit odd that you have problems with Dragon Priests at level 33 that much. You could always sneak attack him if you're an assassin, or hide behind some rock and pop some arrows in him ( altho you'll need like a hundred if your archery is low ) And if you're a warrior, get in his face, shield bash him as often as you can ( replenish your stamina via potions ) and hit him as much as you can. Your followers/pets should make it trivial, really.

Slow time/elemental fury shouts help as well.

Only some though. Netch can be nasty in groups ( especially bulls ) and so can be rieklings backed by a charger. Everything else is not that bad honestly.

Well, you did defeat him, so that's a pretty good sign that your level is high enough. However, being so tactical may have been something new to you. Also, that's one of the hardest dungeon crawls (including, I think, one of the longest) so you may not have to weigh it so heavily. Stealth, hit-and-run, and conjuration are your friends on Solstheim!

True that! I was really surprised by how tough Ash Spawn and Reavers are. I'm playing on Master too, not Legendary!