Not making assumptions, stating my view. Yes, the first beer I ever made was terrible, before the advent of the interweb where information was readily available.
5-6% should be close to correct for an ale yeast but what was the SG?
Question, why are you using a Belgian ale yeast?
Adding more fermentables while it’s fermenting won’t sweeten it, it’ll just keep producing alcohol until you stress the yeast to the point that die off.
Once the FG is around...
I’d honestly be more concerned about the balloon, the use of sucrose and bakers yeast. If you’re just going for alcohol you’re going to get it, it’ll be prison hooch but it’ll have alcohol.