i just wanted to ask a few things about my stratocaster's humming to see if they were normal.

On my friends amp, in between pickup positions does not produce any humming, but on single pickup positions, humming will occur.

On my amp though, humming occurs on all five positions, louder and more "raw" on the single pickup positions. If I turn the tone knob to zero, there is absolutely no humming except on the bridge position, but that's because the tone knob doesn't affect that position right? (?? so do i have like a grounding issue with the tone knobs then?) I've tried taking off the knob and touching the metal part, but nothing changes. A strange phenomenon also is that the hum disappears when a string is vibrating..

If I position my guitar in a certain direction, the humming disappears even with tone knob at 10.

On my epi les paul, i get a hum too, but not nearly as loud as the stratocaster and it has to be a way louder volume level, and strangely also disappears when the tone knob is turned to 0..

the amp is marshall MG10CD
Many strats have what is called an RWRP (reverse wound, reverse polarity) middle pickup. So when you're in positions 2 and 4, the two pickups act somewhat like a humbucker in that they cancel some noise.

Your amp is probably just inherently noisier, so when your guitar is "quiet" you still get some noise from the amp.

The tone knob on a stock strat doesn't effect the bridge position, correct. When you turn it down you're just filtering out high frequencies, which is where a lot of hiss and hum lives. So that's not an indication that there's anything wrong, it's expected to work that way.

This sounds like normal operation for a strat.
Sounds normal. Which amp do you use, and which amp does he use?
I use a marshall MG10CD, i don't know what amp he uses, but I do know that his amp is also compatible with bass guitars, and has more many more knobs than mine haha. but alright, I was just afraid for the strat because I bought it used, and I would like to keep it's resale value at the price I bought it. Thanks a bunch.
Just by the nature of the gear yours will have more hum. There's nothing wrong with your guitar, bud. Happy playing!