I've never grown peppers that way, but there is a man in my town that does it with five gallon buckets. I drive past his office every day, and from the street, the plants look healthy. I assume he is successful with it, since he grows this way every year.

I grew a hot pepper in a topsy turvy last summer and it did fine, but you have to water those things like crazy. The tarp material gets so hot like a greenhouse and the soil gets bone dry. SOmetimes you have to water twice a day. It does work , but in my opinion it is a pain compared to planting in the ground or in a large pot. I never add sugar to anything as I think that is a wive's tale.
Either way - good luck.

I wonder if sugar in the soil would ferment and get your plant drunk. :)

I've heard of people adding molasses to their ferts.
It's more to feed the microbes etc. in the soil rather than sweeten up the fruit,though good soil conditions might make sweeter fruit etc.

I've grown in the topsy turveys. I don't recommend it. Yields are much less than what you will get from planting them in the ground or in buckets, and as simsedward pointed out, they dry out really fast.

Never heard of nor done the sugar thing.