Well you can, you just can't import a GoA character into awakening

. He doesn't have it anyway, so it's irrelevant. Awakenings basically consists of your character facerolling everything though, it's not exactly challenging.
In origins, it's a good idea to do the mage tower first for stat bonuses and wynne early. Honnleath is also a good idea, as is soldier's peak if you want a low strength requirement on the warden commander armour. After that you can go anywhere, though you're still a bit underleveled for orzammar (not at all impossible though, even solo in nightmare).
DLCs give a few useful items, however apart from the high regard of house dace, none are endgame ones (battledress is as well if you're using two rogues). You also might struggle in Golems if you create a character for it rather than import one.