FWIW, I mount everything on a wood panel so I can pull the entire unit, almost as if it were a PCB boardset.
I did something like this, I can unplug everything from the PC board relatively easily and pull the whole board out. There are a few reasons I did this:
1) PC cases generally look horrible. OK you can't see it, but a board looks nicer when you open the cabinet IMO.
2) If you have the front of the PC case at the front of the cabinet, it is a PITA to get to the sockets on the rear (+ vice versa).
3) This is BYOAC, going the obvious route is not an option

FWIW cooling is no problem (for me). I have a 'silent' PSU (fan only comes on if neccessary), 1 'chassis' fan and a CPU fan which I can adjust the speed of. I agree that the fact that everything is not in a small (hot) enclosed space negates the point that PC fans are usually intended for use in enclosed spaces.