Couldn't sleep last night so went through many pages and videos.
I've learned over the years of low budget hot rodding that there is a lot you can get by with, but ... He's trying to build a 10,000 rpm four banger, ok .... Rotating mass is everything! Balance everything, and clearance check everything!
Great job of buying springs to handle the rotational speed, but at least go to the toy box for the play dough and check what will happen with valve float. How about a basic balance job?
What about at least a crude balance job? Even with small block chevy's we used to get the crank, timing gear, flywheel and balancer balanced at a local speed shop. We talked the auto shop teacher to buy a good beam scale (I think we actually stole if from the science department and he covered for us), and we would weigh and massage every rod and piston for not only clearance, but weight. This idiot things he is going to torch cut his clutch and then spin it up to ten grand.
Was a good chuckle having some experience in engines.