I'd run it on straight, fresh fuel first, without additives, and see how it goes, esp as it hasn't run for 5 years.
Carbs will likely be dirty with the old fuel (if the fuel has been drained, rust on the inside of the tank is possible).
I wouldn't use additives as a means to avoid a carb clean; if they need stripping, they need stripping.
What mileage is on it?