Another silly powerful build, we expect no less from you sir! Truly, you are just building a reasonable mans electric mountain bike
That rear shock is just a place holder, right ? I've seen air shocks blow out in short order with much lighter motors than that biggen.
Apparently those QS axles are made of alloy with a high cheese content and have been known to break over 200A. I've got the bigger 50mm version with cast rim for my moto conversion project (my poor mans zero, inspired by the ones you loaned me a few years back! ) and that was the warning given to me when I said I'd planned for feed it 600A.