I started the Devils Crossing bountys and I seem to keep getting the same 2 queats. Kill Nalloth and put whats his name remains to rest. I killed Nalloth twice thinking its a bug but after I turned that in again I got the remains quest again.

Yes, you can do the bounty quests over and over again; that's not a bug. :) It's so you can grind rep with the factions.

As you progress further, more bounty quests become available as more of the map is available to you. Some eventually seem to disappear.