It looks like her feet are suspended a few inches above the ground and only because she's holding then up. She could easily just stand up normally, so it really doesn't look like fun at all.
Nope not for me, I would get board after two minutes, not to mention sore plums.
Yep wouldn't hurt if it was a lil higher, kinda pointless at that leval plus a lil more support in the crotch / leg area. So yeah I would if it was higher and wouldn't make your crotch area hurt with more support.
It looks like you are strapped in at the waist and chest so there should be a lot of support for comfort. Also the straps that it hangs from look adjustable for height so you could get your feet right off the ground. All and all given the right partner to play with I would give it a try but then I tend to be up for anything at least once or twice.
I wonder if it bounce like jolly jumper?