Wow man, great flight!
As for your issues. Sounds like a gain issue. If you are having to move your gains around a bunch and not making any progress than I would check first the mechanical setup, are all the balls silky smooth? Tail silky smooth? If all of that checks out, check your servo resolution. Could be you have too much mechanical gain and your servos aren't able to make fine enough changes at higher gain values.
Just a couple of things off the top of my head.