1) I agree that there should be a plate per job, and so long as they're gonna keep making class specific gear for even individual crafters/gatherers, those should get plates, too. I love the BSM gear, but I can't really justify dedicating an entire plate to it when I switch crafters so often. (which does bring me to another point: since crafters are essentially different flavors of the exact same thing, they shouldn't have class specific gear in the first place. Just lemme put that BSM top on any crafter, dangit!)
2) I heartily agree with that as well, but I imaging they'd either give the spaghetti code excuse or avoid it since it's a (very small) gil sink, and they do try to enforce gil sinks.
3) If you change your classes with a macro, you can set a title within that macro. Every one of my classes has a different one. Here's a rough outline:
/micon [#] gearset (gives class icon of numbered gearset)
OR
/micon "Soul of the [insert job here]" (gives fancy jobstone icon)
/gearset change [#]<wait.1> (swaps to that numbers gearset job, then buffer time)
/minion "[inset minion name here]"<wait.1> (changes minion, then buffer time)
/title set "[insert title here]"<wait.3> (changes your title, and optional buffer time for doing action next)
/ac "[ability name here]" (for if you wanna toggle tanks stance on, or summon carbuncle/fairy, etc. as part of your transformation)
So my WAR one looks something like this (though I'm not looking at it right now):
/micon "Soul of the Warrior"
/gearset change 2<wait.1>
/minion "Hunting Hawk"<wait.1>
/title set "Of Unbreakable Steel"<wait.1>
/ac "Defiance"
4) I just have a mount on the hotbar for each class. I believe there's a way to tie it into transformation macro as well? Someone said something like this, though I have not tested it (and hotbars look different on consoles, which I play on):
/hotbar mount "[mount name here]" [hotbar #] [# spot on that hotbar]