Well I dont find much trouble with the aerial fight in hall of echoes, it looks easy enough. You can always summon a wyvern to aid you in your fight and if you had locate majority of dragon skill book, majority of your important skill should be max as well.
Another solution is to come back later at higher level. Since you mentioned you just lvl30, I suppose you still had a lot uncompleted side quests, where majority can reach lvl34 to 35 before entering hall of echoes. Definitely you need to have a save before entering hall of echoes, since its a 1 way trip.
