Iron Pup
I saw those servos with the screws half way out and almost called you at home to scold you on your set up.... then I read your post. So much for trying to help a buddy out....

Seriously now... to touch on a few things.
1. I haven't heard any rumors of a YS125... would love one, but I do not believe such a beast is in the works.
2. I run 120's on nitro and if you think the 115 shakes, try holding on to a 120 on a SOLID mount
3. My suggestion with regards to servos... I take ply (or some popsicle sticks), and glue them to the bottom of
the servo tray where the screws would attach. Thus making the area twice as thick for the screws to bite into.
Then drill the mount holes, insert screw, remove screw, run thin CA (no kicker), and let the glue soak into the wood.
Works for me.
4. I've known many "gold" pilots to run standard servos on 150+ MPH planes with no ill effect. I usually set up my planes with
a decent servo on the elevator, a plain servo on the rudder, and hitec 225mg's on the ailerons. I've heard many have had issue
with the 225's, but they seem to work OK for me. As for wear and tear caused by the motor.... I've had some race planes for
many years without the need for changes internallly.... as long as I can keep away from Speed the plane seems to last pretty well.

Jimmy Skids