Good afternoon, LB, and ...
Plenty to read and amuse you here, and lots to learn and share. I've never lived in Dublin, but I've read that it's a great city.
Just to humour you, diatonic means no accidentals (sharps or flats, in Western music...). Examples of diatonic instruments would be diatonic accordions and harmonicas, and the dulcimer.
Most guitars and basses have removable knobs, with set-screws, grub screws or simply pull-off. It's a relatively easy mod to do, and so have one's own preferred style of knob on the instrument. That's what I would do if I didn't like 'em (and have done, several times...). No big deal, I say.
Most..? Much modern pop, perhaps (but even then, perhaps not...), but I'd reckon that most music contains accidentals; often lots..! The music that I listen, to, compose and play certainly does..!
My car radio doesn't have 18" speakers, but I can get a decent reggae sound from 'em. (Or at least, I could if I listened to reggae through it, but I don't... ). Speaker size and 'tone' are not directly linked. Think ear-buds. No good for reggae tone..? Hmm...
Indeed; if the instrument is of decent manufacture and has been stable for the past forty-odd years, it would be detrimental to alter anything. Best left in its current state, strung up with balanced string/truss rod tension, in that case.
Get a high-quality studio photo of each bass printed up, full size. Frame and hang those on the walls, optionally with attractive lighting; leave the basses in their cases in a secure, temperate room (not the attic...), to be taken out and checked up on regularly (quarterly..?). That's how museums and art galleries keep their produce intact for so many decades.
The 'skunk stripe' is a sliver of wood covering the slot routed out of the neck to allow for insertion of the truss rod. Not all Fender guitars and basses have their truss rod inserted in that fashion; they would have the slot routed out under the fingerboard, before it's glued up. It's not an aesthetic stripe; it's part of the way the instrument was manufactured.
Just sayin'.
I can't agree with that. There are some excellent methods out there, on theory, technique and/or composition/harmony, plus transcriptions of 'greats'. Not to say that listening isn't useful (it is...); reading (or rather: 'studying'...) has its place too.
In that case, if it's unavoidable, best embrace it as a 'feature', and take reassurance every time one's thumb feels it, by thinking 'Ah, yes, it's still there..! Good..!'. Make a 'positive' of it.