Responses from nhorton

DIY Equipment and Speaker Stands
Turns out audiogon doesn't like ASCII art, I guess there will be no sketch. 
DIY Equipment and Speaker Stands
Spouse aproval on DIY stuff is difficult. The best thing I know of for DIY speakers stands is to drive three or four REALLY thick nales (like masonry nails) through a board that is about 13" x13" and then use screws to attach an identical board ov... 
Balanced Cables/Terminations Question
Basically (in any case you should ever encounter) yes, all XLR terminated wires are balanced. For termination options, XLR is the only common termination option for balanced cables. Theoretically you could have a balanced cable terminated with pow... 
Use of Balance Control feature
Tom is right that adding circuitry always degrades the signal. Thus a unit that includes the control will sound wors than a unit without the control if they are otherwise identical. HOWEVER, if you are asking whether USING the control will degrade... 
Cleaning LP's
Look on Audio Advisor, they have cleaning solutions in every price range. 
XLRs vs RCAs
Lost failed to live up to his name and is totally correct. In many cases RCA wires will sound better that balanced because in designs that are not really balanced, there is just an op-amp at the output of the component generating the balanced outp... 
Buyer's remorse - your worst purchase?
I upgraded to an expensive Surround Sound Reciever from a lesser receiver and wish I had taken the oportunity to go to two channel then. It ended up being two years later that I dumped surround for pure stereo. 
The Fourfold path...which way to go?
I personally am a fan of tube pre's with ss amps. If you really want tube sound, it is a good way of getting it. 
Room Acoustic Treatment
www.silentsource.com, particularly for acoustic foam (like Sonex panels) 
Signal to Noise Ratio
That is slightly different from my understanding. The term Signal to Noise Ratio is just that, a ratio. My understanding is that the idea is a 100S/N ratio means that for every 100 dB's of signal, you get 1dB of noise. Thus you want as much signal... 
Small Dedicated Listening Room???
Acoustic treatments are your friends in that sort of a situation. If you treat the room, there is no reason that it should sound poor. 
Speaker recommendations
Price Range? My general suggestion for anything under $1k is Paradigm speakers. 
Extreme low volume.
The reason it sounded like the radio was because all wires act as antennas. You will find that if you hook up a long unshielded cable to any stereo with any component on the end, you will hear the radio. The fact that you only heard it at max volu... 
Need a good inexpensive stereo pre!
For inexpensive preamps, the Creek stuff is very hard to beet. 
Cartridge for Rega Planar 3
I know it is over your price limit, but at $300 the Grado Platinum is really an amazing value. I think the extra $100 would be worth it for that cartridge.