Just wondering; is this guy supposed to be able to shoot fire/freezing etc through walls? Awful hard to fight him when he shoots from outside the screen where I can't target him and through walls. I have to believe it's some sort of weird bug.

Only fight with this dragonrider when solving a second quest for Warrior Guild. Otherwise it will not drop dragonheart and You lose a chance to upgrade Your armor! Don't try to fight him without drinking some elixirs first. It's a pure suicide to fall under his fire without having at least 90 in fire resistance.

I have some light armor due to low strength and a few pieces of enchanted jewelry but, probably no more then 30 fire protection. But still, there's no way of fighting him when he shoots from outside the screen and through walls. Impossible to target even with area attacks. I don't remember him doing this the last playthrough but I didn't use the hit and run ranger technique that time either and my then mage had powerful spells.

I don't recall that ever being reported before. In fact, the layout of the room is such that you should be able to draw off most of the other opponents there before engaging with the dragon rider.

I don't think you can trigger the fight if you don't have the quest (IIRC he stays neutral and doesn't trigger the conversation when you approach).

I was using ranger techniques as the little magic I had, including most arrows, had little affect. Basically shoot the magical arrow spray to get multiple hits with one shot then run for it and repeat. Most of the battle was within the cave, not the initial room. Perhaps that triggered the problem? It really was weird; a red flame or blue freeze spell would come from off screen and penetrate the cave walls and either froze me or fried me in the process. I literally did not see him or his dragon. Perhaps my resolution is too low? I had crash issues (actually, the game, except for the sound froze so I could do nothing but <CNTRL> <ALT> <DEL> to close the game) with higher resolution even though I'm using the GOG addition via Galaxy so I went to the default of 800/600 but it seemed I could see a larger area when I used a much higher resolution. my English teacher from elementary school is probably rolling in her grave with that run-on sentance I just did
I did manage to draw off most of his helpers. The ones I didn't get stayed in the initial room anyway - only the dragon rider followed me into the cave.

OK, went back two saves and fought again. Found a new tactic other rangers may be interested in. Fire and immediately move a short distance left or right (heal if needed), repeat. No running needed. If you move fast enough, he misses. Just don't assume safety around a corner because he was still firing through the walls - but by not running, he doesn't start firing off screen. It didn't take very long to beat him this way and by staying close, the arrow spray gets more hits.