This is the guide I used to setup wow on my Steamdeck

It works very well. Gameplay is smooth but you'll need to run lower graphics settings.

I've played ranged and melee classes without any issues. Depending on your button mapping/key binding you can get up to nearly 30 buttons for abilities. More that you would need for any retail class, not to mention classic.

I've never noticed the device getting hot or even heard the fan run.

In the guide I linked it talks about how to setup curse forge on the steamdeck. I don't run a lot of addon when I play on the deck (console port, immersion, and dynamic cam) but they run without issue.

Hardest part was getting the buttons set up.

If you have a little extra money or a 3d printer the Deck Mate is awesome. I use the little kick stand to prop up my Steamdeck on the coffee table while I watch TV.

I've not had too many problems jumping on for world quests on the steam deck or levelling some lower levels in dungeons. I mostly stick to my BM hunter or Evoker as they're just simpler.

Can't say I've had issues with temps being uncomfortable, but I haven't checked the numbers.

It runs with low/medium settings at 60 for me with a couple of addons.

I have played retail World of Warcraft on my steam deck without locking it to 40hz. It was satisfactory while flying around in Valdrakken and in the few quests I did. I was surprised at how well it performed. I can't say anything about playing a pet class or addons not working, but the controlls with the controller addon worked great and my fps never fell below a threshold that was annoying, and I'm pretty senesitive to fram rate issues in games. It DID get really hot if you touched it in the wrong spots but it does thst for lots of games I play, if you stick to the handles it doesnt get too hot to play.