considering its an operating system I don't think you could delete everything because some applications are in a runnning state. However it would completely fudge it up.
I wonder if a restore would work in this deleted state?
Surely the recovery mode is part of the firmware not the operating system? So in theory you should still be able to put it into recovery mode.
I don't believe the jailbreak gives you access to the firmware files, just the OS files.
You sound correct to me.
Still, what is the difference between firmware and operating system? Like they call it "firmware 1.1.1" for the iPod but isn't it "operating system 1.1.1"? And in what language would the firmware be written? Like, is it completely different to the operating system?
Matt