Your squashed butt says your AOA is high, right there. About unexpected flicks: see butt sensitivity and aircraft design, above.
I don't understand this. Are you saying every time 'G' squashes your bum you should ease off because the AoA is high? I don't see how you'd ever complete a loop if you did that!
The trick is to pull as hard as you can but not so hard you exceed that stall angle. To do that, you need to know when you're approaching the stall angle. To do that you need an aeroplane that buffets before it departs (the Chippy) or an AoA indicator.