"Since the Clear Mirror uses an electrical heating pad to warm the glass, is there a chance I can suffer an electrical shock?"
The Clear Shower Mirror is Underwriter Laboratories (UL) and C-UL listed, tested to the CSA interantional standards. The low voltage ensures electrical shock cannot happen.

"Can I install the Clear Mirror horizontally?"
Yes. If you would like a wider view, maybe for two people to share at once, feel free to. You need to alter the installation directions yourself, paying close attention to the Clear Mirror height, sink centering, and the cutout location.

"If I didn't place the adhesive heater squarely on the back of the mirror, can I pull it off and re-stick the pad?"
The heating pad has been designed to be very sticky. If you attempt to remove the pad, it will probably get ruined.

"Can I use regular cleaning supplies on the mirror?"
Yes. Use any normal glass cleaners and mirrors cleaners. Since the mirror is heated, don't use combustible or toxic substances.