Had the same with mine - managed to get just enough purchase on the plastic ones for them to have stayed on for a while now but they will be replaced by alu ones next time they fall off.
Use the steps app to see if there's a firmware update for the motor, latest one smoothed the transition of how the motor switches on and off.
Inner tubes as supplied are heavy DH ones so tubeless is a must. You will need tape and sealant. Mine went up easy with a ghetto inflator and soapy...
Having tried the battery in both of my bikes and it not work and my other battery working fine in both of my bikes, I'm not sure I agree with you but it's getting one final check before the battery good back to Chain Reaction.
Try to re-pair the unit via phone Bluetooth settings before opening the app. Mine can be problematic to connect quite often but don't this usually sorts it out