A: As long as you keep it well away from water per code.
A: You can barely see the dots of the lights. I put ours on a dimmer which makes it nice to adjust the brightness. This picture is with them fully bright going up the stairs. I hope this helps you.
A: These work well for me, but two main factors will determine well they'll work for you. First, how glossy is your floor finish? High high gloss will reflect like a mirror. Second, how bright are your LEDs? I'd guess you are not using your LEDs at full-brightness, because it's just accent behind the TV, so these will be perfect for you. Check my video to see them in action--I have some very, very bright LEDs loaded into them and you can see if it will work for you. Incidentally, at this price point, it's absolutely worth a shot, and Home Depot is so good about returning products.
A: We put them under our kitchen cabinets and do not notice a glare on the countertop, not .sure about a wood floor.