No
Medium cage.
I work at a Go Kart Repair Shop and the current age limit to drive a go kart around a neighborhood area or similar scenario is 13 years of age. As long as you can drive the vehicle safely, you are good to drive a go kart. I hope this helped you in your needs.
At a go kart place
Its 1100cc on a go kart :D
Where can I driver my go kart
There really isn't much to fix on a derailleur cage. The guide and tension pulleys can be replaced, screws can be tightened, but that's about it. Straightening a bent cage is possible, but it's really hard to get the alignment back close enough for the derailleur to work properly. I'd buy a low-end replacement rather than attempting something like that.
This is a shop-n-go kart.
A box car or a go-kart is simple to make with some wood and four small wheels. If you want a motorized go-kart then it's more complicated but you can probably also make one if you are prepared to work on it. See the attached link for a basic go-kart.
go to a go kart store or ebay!
The Mini Beast.
IT would very much depend on the vintage and quality of the bike. If it's a fairly recent bike I'd just buy the cheapest Shimano derailleur with the correct hanger (either bolt on or integrated) and the odds are good that it will work.