Responses from mlieber507

Good entry level cables
14 gauge stranded twisted pair that is cut to size, with no coiled up slack, will perform as well as anything in runs of 10 meters or less. 
$1000 bookshelf speakers with "recessed", "laid back" or "flat" mid-range?
You might like NHT classic 3 speakers. 
Magnepan, Ohm, Spatial or ??
Martin Logan makes several large panel electrostatics which provide really excellent  sound.  Some Best Buys have them on display. 
Passive Bookshelf Speaker Selection
You should get whatever electronics aside from speakers first.  After that is all set up, buy speakers from someone who will let you return them if you don't like the sound.  Also you could try the used speaker market and some of those dealers wil... 
What could cause this amp to fail?
There probably is a junction transistor phase splitter circuit driving all of the final output MOSFETS . If this develops heat sensitivity it could put a DC potential at the speaker terminals. The relay circuit is there to detect this DC and shut ... 
Your One Bullet Point Solution; Electrical Upgrade
You might want to consider a Power Conditioner.  It takes care of surges as well as smoothing out power dips and other power line induced noise. 
SET the best?
If you like what you hear with an SET based total system, and can afford it, then that's the way to go.  However, if low efficiency speakers make a come-back and you like their sound better than your SET based sound, you'l need some new electronics.  
Ported versus sealed speakers: is one type better?
Generally, sealed box enclosures, there are at least 3 types, have flatter base response curves than ported enclosures, but are less efficient.  Some ported enclosures have passive reverberators covering their ports to enhance efficiency, base con... 
Best small, desktop speakers, $500 or under (new or used)
You might like Adam Audio active studio monitors.  
Why don’t tube amps sound like tubes anymore?
Improved engineering 
Does altitude change the sound of speakers??
The effects of gravity are reduced at higher altitudes. Thus, it is slightly possible that a speaker cone will behave slightly different at high altitudes compared to sea level. It would not be audible. 
Why do you think Bi-Wiring improves the sound ?
With one set of binding posts on the speaker end, in theory, unless you are modifying the connections to/thru the crossover, the only benefit would be thicker wire.  If the speaker has 2 sets of binding posts, and they give you a choice of paths t...