Well ... What if the rudder was bigger, and possibly look to the Bell P-39 for inspiration concerning the overheating? (I agree with you, because taking off would be difficult in the configuration shown...wouldn't the oil boil up on take off because the radiator wouldn't be able to cool it?)
Just thinking out loud
the 39 had its radiators in the wing roots and all that. at least it "had" Radiators in places that made them effective.
this one has small Radiator around the back engine, and it is made in a way that it cannot be.. effective.
A lot would need to be changed to make this thing... take off.
rear rads under the wings, 109 style.
a few degrees to lift the outer wing.
a place to store any substantial amount of fuel...
and the ineviteable droptanks, because internal fuiel still will not suffice.
and the rudder.
But as above...
i would not want to have this in my Lolwaffle.