Thanks for keeping us posted terrace. I think your reports are generally in line with my own experience - tuning those things is more or less a black art. I've found some of the same issues with chainsaws, but the bigger engines seem to be easier to tune. If you keep the fuel clean and store them with the carburetors empty, not much goes wrong. I did have one chainsaw that was always hard to start, and the best efforts of a mower shop didn't make it any better. I donated it to someone who didn't want it either - it was accepted because I included a much better saw in the deal.
The moral is, small cheap two strokes with big carburetors are a pain in the backside, but they needn't be unreliable, just nasty to operate.
