Kidding, of course! I assume you mean the TV room connects to other space. If you set up the room so the 'missing wall' is in the rear half of the set-up, that shouldn't affect the sound too much, just don't rely on reflected surround sound.
As for the fan, I used on on my first surround receiver (Dolby), which was one of the first ones on the market, the Pioneer VSX-5000. I stood a 4" pancake fan on edge behind the receiver, blowing away from the receiver, drawing air into the perforations. Kept it cool, but it pulled a lot of dust into the receiver, which, in retrospect, probably created more impedance to cooling than helping it.
The manufacturers are usually good about designing their units to keep cool the way they come, using natural convection (heat rising). Those that need fans come with them. However, if you have your equipment in a cabinet, you definitely should use a fan to boost air flow in its natural direction, i.e., blowing in at the bottom or out at the top.
Larry
Oh, and Mike, the vacuum-tube printing needs a cooling fan, too.
