There is a problem with pitch stability. You can see this as the pitch angle moves up and down 5deg or so back and forth quite a bit. This isn't turbulence, it's wallowing around. When he gets it trimmed nice and stable it will stay there, but if disturbed, it's back to unstable wallowing again.why doesn't he find out how slow his plane can fly so he can dial back the speed some?
I'm pretty sure at this stage that he's too scared to fly it to an actual stall because there's a good chance it'll deep stall and he'll have to pull the chute, and write the machine off.
If that happens, it's game over.