is not it weird for some non-avialan coelurosaur to
have such a long forelimb in general and humerus in particular??
Certainly, and that's why the authors think it "might have developed a
functional airfoil".
To me it seems strange (likely autapomorphic) the very developed
tarsometatarsus, some more informed person can say better.
What do you mean? There is no tarsometatarsus -- the metatarsals aren't
fused to each other.
The apparent fusion of metacarpals II and III is strange, however. It
suggests "a functional airfoil", I'd say; but then, animals like
*Archaeopteryx* lack this fusion.