They are kind of fascinating once you get over the creepy factor.

The main problem is that, like rodents, they can be a major health hazard as passive disease carriers. A pet rat is as different from a wild rat as a pet roach is as different from a wild roach.

Very true. I also raise Dubia roaches, which are very different to those common in the western world

How many would eat all that? What about their waste how big would it be?

So I have about three hundred at any given time. As for waste, I don't worry too much, like fish the young eat the feces of the adults. In the last six months or so the 60gallon tubperware they live in has accumulated enough wase to cover the bottom about an inch deep or so

You have 300 roaches in a 60 gallon tub? Are you raising them as food for something else or just for fun? I'm certainly not one of the "eww roaches" people but I have to say I don't see the appeal myself ;)

I have a lot of very hungry reptiles, I rescue unwanted lizards and turtles.