It actually sounds like you may have a defective touch-screen or something, the scrolling inertia is pretty good, if you swipe down hard it goes pretty far but if you do it lightly it doesn’t go as much. I would find a friend with an iPhone and see if it’s the same, and if it’s different bring it to an Apple store and have them look at it.
You clearly have little to no understanding of how a computer works. Running multiple processes at the same time has nothing to do with the file system. Further, to say that OS X and iOS can’t run multiple processes at the same time is just not true. Anyone who has ever gotten a push notification while playing a game or using any other app is using more than one process at a time, the push service (as well as a bunch of other internal processes like the Mail app, the iPod app if you’re listening to music, etc) and whatever app you’re using at the time.
Jailbroken iPhones and iPads can do the things you mentioned, run animated desktops, run multiple apps on-screen at once, etc – and jailbreaks definitely don’t change the entire file system of the device.