Why does the engine move with vibration? The bolts that hold it to the chassis (from the bottom) should hold it well. Are those bolts tight?
You need to sort this out first, it needs to be rock solid.
Thank you for posting pics.
A good way to tell if its sucking air from somewhere is to put your finger over the air filter neck, and try to shut it down. Once deprived of air, it should stop almost immediately. If it keeps running, then you got an air leak.
I find this hard to believe since its...
If the engine starts at high RPM, your carb idle gap is too big.
Remove the filter and re-check. Or post a photo of it pls?
Have patience, Nitro requires patience and is frustrating to begin with, but very much rewarding in the end.
Thanks