<<4.  Does the bigger tail have any effect on CG (the CAFE plane had the
extended engine mount and the small tail)?>>

You would have to know the weights of the two tails to determine any CG shift.  The big  tail is carbon, the small tail is FG.  The larger tail does, however, buy you approx. 1.5 inches of additional aft CG range.  The published CG range remained unchanged, so for the same CG position you end up with additional stability.

Chris Zavatson
N91CZ
360 std