RE: Hinges ca or not to ca..
I had this plane and used H9 CA hinges.I plowed this one into hard soil,everything but the hinges broke...
Those servos are plenty.I had mine with regular sport JRs and a Hitech 645 on rudder.The 160 is tons and nearly excessive power.
Dont use a gasser,the Katana will be overweight,without question.Seal the gaps.The Katana is an honest clean flier,but somewhat limited in the 3D category,but will try to please and is enjoyable.
Good luck with her.
I had an OS 120 Surpass,plenty for scale aerobatics,a Saito 150 or 180 or YS 140 or OS 120-140-160 2 stroke will do well for performance aerobatics some 3D
A G38 or other 40cc gasoline will burden it to the point where the fun is short lived.