Robert,
"Is there much and/or frequent maintenance required to maintain the mirror like finish on your bundle of snakes?" Very easy care, I simply wipe with a clean cloth and once every few months I may do a light chrome polish.
"Now, back to the heat/heart of the matter. Since yours are polished SS, did you have the interior of the pipes ceramic coated?" No
" If so, do you believe that process was noticeably effective for reducing rear heat, or did you acquire the vehicle already equipped that way?" I applied\glued a thermal barrier to the underside of the rear clip that sheilds the heat of the mufflers.
Tim