I have seen different people putting inter tubes between the motor and frame to isolate the vibration from the frame? looks shabby way of doing it. the tape is very neat way and looks good too.
Will this cause a problem electrically, if so why can't you just make the motor the ground as in cars. Otherwise what is the other reason's not to do this, I would think it would keep bolts and such less pron to loosen. haven't mounted the engine yet, going to replace the studs as you said with grade 5.
I saw you have a kit for this for $9.00 would like to order it.