Your post does however rather prove my point. You clearly have neither judgement nor humility, god help you on the day that it is needed.
Without wanting to tell you things you have no interest in, then to your own "humble" information i can inform that I, just like many many other professionel pilots, started flying single pilot on everything from piston to complicated multi-engine a/c in commersial operations all over the world, from the tropics to the arctics..... and yes once again... single pilot, before i started with the airlines in multicrew operations.
Also therefor i know what the difference is between airline flying and GA, and the gap is big, even though the experience gained by GA is generally really good. Just a pity that single pilots often works better alone, hence = not a good idea to take up front when we are busy.... sorry!!
A person with your attitude is the kind of person i would avoid on the flightdeck at any time during an emergency, because your ego seems much greater than your knowledge, and that can potentially create substancial amounts of extra negative work to a guy/girl up front after a pilot incap.
A company pilot positioning or a cabincrew to help out is the most safe as i see it. And true, modern airliners can fly them self if not too many technical failures, so it's not really the big problem to land it singlepilot if need be, ...... so still no need for eager hotshots wanting to have a go at it!!!
Might be time to close this one!!!