So...I have hopefully reached the end of this saga...and it did not involve matches or a mysterious sinking...
I finally gave up and dropped the boat off at a repair shop on the coast that I saw highly recommended online on some local Facebook pages...
I spoke with the owner and explained what was happening, he told me he was flat out but would get to her when able. No worries, it's worth the wait if he gets to the heart of this problem that has plagued me for the past several years... So, a month later he seems to have finally chased down the multiple gremlins and sent me a video of the old egg mixer firing right up cold and running like new!
Turns out it was a combination of problems, but they all boiled down to fuel starvation. Fuel pump, priming bulb, fuel line, water separator, anti-siphon valve, carburetor reeds, carb cleaning, and someone along the way replaced one of the carb screws with the wrong one.
I'm picking her up tonight and he asked me to get on the water ASAP and run her hard to make sure the problem is resolved. I can't wait to actually get out and enjoy my boat again!