As I said this motor angle is a compromise between safe prop clearance, model size and optimal air injection. "Normal" motor angle would be better like the Chinese XTWs' have (not Japanese), but my props, motor size and aimed model size don't allow that configuration.
"Problem" is a relative term
I will have pitch problems after a certain speed, but I hope it will have a speed range where it will be fly slow and stable (like the Flatwing).
Pitch down after throttle reduction/cut is actually useful in the streets since slowing down, or stopping should be fast.
The other problem is slow speed turning, mainly on the ground, since prop wash won't have an effect on the rudder. Perhaps I will make a small retractable wheel or something like this.
Enjoy your vacation!