Massive document you have there mgshightech.
I've been living off solar for maybe 12 years now and share your findings re MPPT with solar panels. I just bought a new 60A reg and went for the PWM version for the half price. As I understand it, with the way we use our system MPPT won't help us much but as will all these things you have to look at your personal power usage habits etc.
If you plan to do anything I would suggest it is capable of handling 12, 24 or 48v as they are the common voltages for smaller RAP (Remote Area Power) systems with 12 and 24 being ubiquitous in the RV field (my main interest). I do however have an least one acquaintance with a 1000v string of panels, but keeping things < 50v makes life a lot easier.
After some teething problems (Paul I see there's an error count of 1 at present) Paul's PID system seems to be working well, so much so that I seldom log in to look at the graphs now because they are always flat-lining at the set point 
I'm interested in this but my current project will really take up all my time for the moment. It is slightly related to this though (a SCADA-like network) and I plan to have it at least monitoring if not also controlling RAP systems.
Rob