Hopefully I can answer your questions satisfactorily.
1) Switched outlets are what they seem. There is a switch on almost all surge protectors and the outlets marked as 'switched' are the ones that are controlled by the switch. Turn off the switch, those outlets go dead. The ones that are always on are, you guessed it, always on regardless of the surge strip's switch being on or off. If you have 2 always on and 6 switched, then you still have 8 usable outlets.
2) As long as you keep the extension cord short, and heavy duty you should be ok. You can go to most hardware stores and pick up 'doglegs' which are heavyduty, heavy gage short extension cords. They make them for power tools and stuff so you can get between 3 and 9 feet without problem in most places.
I don't 'think' that a short, heavy gage extension cord would cause problems with a line conditioner as long as it (the cord) is of a decent quality. I wouldn't hit up Big Lots or the Dollar store to get them though
. I would think that a short good quality extender wouldn't cause you any problems with your conditioners and such, but there are far, far more educated and experienced people on the board so hopefully someone else will chip in as well.
As far as your last question concerning the Adcoms and Brickwalls. It would seem that at first glance they are all compartively the same with the exception of each company's tweaks of the licensed technology (line conditioners and the like on some that aren't on others) and I really don't think you could go wrong with any of them but again, I am not much help here because I'm not the audio/videophile that you'd need to ask.