Imma address a few questions and maybe a bit more info on my tank.
I know all fish have the potential to jump, but i guess it's all a matter of the tank. In my tank, most of them seem to roam around the bottom and the middle, and none of them do any crazy dashes from the bottom to the top of the tank. The only time they come up to the top is when they see me standing there, which they know it's time to be fed, then they come up.
As of right now, i do have a top that i could put on, but it's made of glass, and with the T5, it seems to make the water a bit warmer, which i don't want. Plus i like the look of the topless tank haha.
As far as the QT goes, i didn't want to put both of them in there because i feel that once i put them in the tank, since they have been near one another, they might team up and destroy my tank. But on the other hand, maybe being in a small space with another fish, might soften them up a bit and give me no troubles, who knows.