So KA spells are as I suspected, its going to be pain to level them. Looks like I have to open up my wallet I am in the process of getting the crafted mount but its bit slow since I play at odd times compared to my friends and its easy to loose a roll in a PUG. But this is my top priority in game now! You are right about implosion so its going to be either first or second spell to upgrade on my list now!
I'll have to recheck some of my SK parses but from what I can remember Feedback Loop definitely is up there for damage output.