Bearcat, there are enough people on here with vastly more experience than you telling you what would happen.
You seem to have a VERY high opinion of your own abilities. What you do seem to lack is humility! Such an attitude would NOT make a good airline pilot. Realise your own limitations.
Regarding people landing 747 full-flight sims - the instructor probably had "Crash - Inhibit" turned on - and wind set to zero!
Also you seem to have completely ignored the response to the problem of slowing a big jet down. A 737 has significantly less induced drag than a PA-28 - it does not have that big drag-inducing whirly thing on the front! Trying to descend from cruise AND slow down at the same time can be VERY difficult. Even Air Traffic Controllers don't seem to realise how hard it is when firing out combined "Descend... and reduce speed to..." clearances!