Ya Im aware they will dry up, but for a single character getting to 50 this is pretty sustainable. I know everyones different, but I saved all my Leves up til 40 and had quite a few to burn through. As for side quests, they are plentiful and if they add more in the future it should still be viable.

I would like to see mini-dungeons 1/2 way between Full dungeons and Guildhests. That would be pretty fun