Both of those are concerns that I thought about.
1. Heat is not an issue, I've checked many times, there is a ton of air space under there to keep the amps cool.
2. The carpet will be getting cut and an acoustically-transparent fabric will be stitched in above the sub. Also, for the record, carpet will do very little to muffle the low frequency vibrations of a subwoofer, and it is almost entirely unnoticable as to whether the carpet is covering it or not. (I've listened MANY times in the last couple years with and without and couldn't really tell the difference beyond my own percieved range of placebo).
Either way, it's been years since that setup was put in there, and I have no complaints and have had no problems whatsoever. There are no heat issues, and the sub sounds great. Some small changes will be made still, but nothing that will significantly affect the setup, so I doubt I'll take any new pics when I make them
.