Yes - hum is caused by pickups picking up (hmmm) ambient electromagnetic signals from nearby equipment.  Feedback is a form of hum that 'feeds back' between the pickup and the amp (usually) - and causes that squeal used to effect by Hendrix.  Humbuckers are pickups that are reverse-wired (in series) on basically two pickups that act as self-canceling fields to remove (or significantly reduce) hum.
I used to own a Les Paul.  Excellent tone, but it doesn't fit with all of my styles (mainly neo-classical/metal w/trem work) and very expensive equipment (cost more than my Steve Vai Jem).  Great for Jimmy, Slash, and AC-DC, but sucky for Satriani, Hammet, Yngwie, Hendrix et al (Ibanez/Fender guys).

No dust - as much as putting the guitar in the case puts it out of mind (as it were), I'd rather keep the dust collection to the vacuum, thank ya very much.  With housing development nearby, the dust has been atrocious.  My computers now have filters in the intake fans to keep my machines from clogging and overheating.  The guitar stays in the case until required. :)

C makes it easy to shoot yourself in the foot. C++ makes it harder, but when you do, you blow your whole leg off.

 -- Bjarne Stroustrup

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