I don't really see a problem with 3, at least on the DM side.
I make high-fantasy scenarios at tier 3+ do it's not like I'm afraid of a everyone having access to magic in some form.
Spellcasters can obtain magic items too.Thanks for sharing your experiences!
I think the only reason I never encountered player disinterest with martial PCs is because in 1E/2E you had a lot of magic items for martials, as well as things like claiming land, building armies, etc. made it interesting.
I never had the experience with your issue #1 or #3, though.
IME That was the where the chore and favoritism came from. DM would have to shaft casters on magic items or they could easily overshadow.
"The chest contains a +2 longsword, a +1 dagger, a shield of fire resistance, goggles of the night, and a wand with 1/4 of its charges"
Maybe that was just NY DMs.