Nathan, no the boat won't die using the fogging mixture...our's just idles rougher while on it. The main "protectant " in the mixture is just the heavy dose of 2-stroke oil.
FYI, Merc recommends running the mixture through a Cool Fuel equipped motor, which is what you have, for 5 minutes at 1300rpms. What this does is ensure that the mixture has pushed all the non-treated fuel through the system, and is for sure making it to the cylinders.
I took the Merc mixture and reduced it by 1/5 since it takes less than a gallon to do our motor....1 gallon of gas, 1 16oz bottle of cheapy 2-stroke oil, and a shot of Sta-bil.
"Toy Story" Y2K 266BR
454 Mag B-3