My load is about 30 pounds and the CEM40 can tolerate up to 40 pounds.
My balancing is alright in RA, but I must say I have trouble balancing in DEC, as there appears to be a third axis for the center of gravity.
As for polar aligning with a guide scope, I could in fact use the small iguider which came with my CEM40 mount. Its focal length is too small to guide a C9.25 - and anyway I am using OAG -, but it should be sufficient for PA.
I am also going to lock the az and lat hex screws.
As far as guiding efficiency is concerned, these are certainly very good leads.