I have noticed that my USB pen drive (no cable) speed is a lot faster than my ipod speed (with cable)
nope, itunes and ipod are just slower programs with more data to transfer. however, the speed is so fast that the length of the cable does not matter at all
Electricity travels half the speed of light, which is 186,000 miles per second. So a couple inches/feet of cord would NOT affect the speed, at all, in any measurable way. iPod's simply work differently than hard drives because it's an entire hardware, rather than just a memory dump.
No it does not. It is based on the driver used by the hardware.