the 3mill laminate is certainly strong enough to replace the glass, if you take into account the huge contact surface with the wing.
10 millimeters is a little too much
I'd say 10mill means 10 millionths of an inch or something like that. the 10mill thing is less than half a millimeter thick. the 3mill is even thinner than paper.
I will not need to glass the motor mount. the way I build it it's already epoxied to the main wing spars, much to the delight of my neighbors (makes the plane twice as loud