you are correct, plugged carbs and flooding carbs will both make the bike run like crap on a stick
I was trying to go back and see what we could learn from your experience.
I guess the difference is a plugged carb would make the bike run lean, and the plugs would burn and turn white.
Flooding carbs would make the plugs wet and black, which is where it all ended up. Since the bike was acting up when you got it, you didnt know how old the plugs were, so its hard to analyze the bike like you would if it was your own.
If the bike sat for 6 months to a year, all in all this is another poster-bike example of the need for liberal use of SeaFoam (before the bike sits for a year).