Next I'd take a look at the steering head bearings. Put the bike on centre stand and check for play both forward to back and left to right. Get someone to put their weight on the rear, to raise the front wheel. With a single finger on the handlebar check the free movement, feeling for any stiff spots or notchiness. Balance the bar central and let it fall, don't matter if to the left or right but they should fall all the way on their own.
Treat everything in life the way a dog would- if you can't eat it or foc it, forget it.