1. 350 wpc, wth, what speakers do you have?
2. 132 lbs (or more), add the cost of knee surgery (torn meniscus) or back surgery (herniated disc). Wait till you get old, know any teenagers? I just changed my 15" woofers. Speaker weighs over 100 lbs (but less than 132), all I did was tilt it, lower it on a blanket, back off, change the woofer, tilt it back up. Not a hernia, but my belly and back are just calming down 4 days later. I tore a meniscus moving an 80 lb McIntosh amp.
3. leave on, that is absurd IMO. Believe in warm up, ok, on, 20 minutes, listen, OFF! Aside from wearing out parts unnecessarily, heating up the room, consider conservation: it is just plain irresponsible to waste electricity.
4. ac. run the room a few degrees cooler, then turn it OFF for a listening session so there is no fan noise or gets too hot too quickly.
5. block ac vents?
They make filters, and shutters, so you can let the house cool, and partially or completely block the vents in the listening area
a. near any speaker so the heat does not dry out the cones
b. near your ears.

