Yes, removing the back 3 kites seemed to remedy most issues it was experiencing. Also made it a bit easier to handle.
Thanks to Jeff we figured out that the back 2-3 kites were leaning a bit further back than the rest, so the angle of attack was progressively changing as you went back, and which is why they were flailing out of control most of the time. I need to go through all the train lines again and make sure they're equalized. I'm sure I'll find the back 3 to be off. I've noticed those lines are lighter gauge so perhaps they've stretched out over the years. Maybe I should pick up some Nexus stacking lines and use those, hmm.
I took the 7th one off because it broke the spine at the bottom for some reason, need to find a replacement rod or put a ferrule in there now.
Thanks for all the tuning/tangling help guys!