As A BST Main In XI, I Stand By The Notion BST Should Not Be A Class.......

[Akamadoshi]

The current limited job we have is "Blue Mage". So I speak from what we already have as I do not know expectation of "BST".
From my own opinion (and it is very unpopular so please do not take it offensive) I do not find the appeal of "able to do MSQ/every content" on BLU.
The BLU with combined spells and knowledge becomes a one-shot on enemies. Wait on cooldown - next. I can already tell by now that once they implement it the way you ask (And I understand why you ask!) this very problematic non-stop demands will follow:
"Make dungeons sync to the difficulty of limited jobs" .. "Make dungeons harder for limited job"... "Do this to make it better for classes"
People already are on huge lists of demands, and when they meet the demands there is even MORE demands, and soon people find it regretful they even asked.
Just like the 2 minutes burst window, which is a very good example, they listen - but now people want it away.
You mention wasting resources, but I like them to keep doing what they are good at, and not breaking what isn't broken.
Even if your idea sounds appealing, and I like it, I know it will not work with the current system/gameplay.
There is SO much more priorities I wish them to focus on, and before we even know anything about BST, I think already asking for how you'd like to see things is too son.

[BelegErkhten]

The current limited job we have is "Blue Mage". So I speak from what we already have as I do not know expectation of "BST".
From my own opinion (and it is very unpopular so please do not take it offensive)

No one is offended by saying BLU is unpopular, because it is. And the only reason its unpopular is because the game "Doesn't let you use it" to run roulettes.
(You CAN run them btw, you just need a full party, and this is in place to prevent people from Griefing and making duties take significantly longer than they should. That still happens sometimes tho lmao, did you know you can reach 80 on BLU without learning a single spell other than Water Cannon?)

FFXIV Blue Mage's unpopularity is directly the result of this game's player base drinking lead paint and being allergic to forming their own parties.
But that of course is just the world we live in, in 2025 when no one has friends and everyone is afraid to talk to other people out of fear of offending someone.

The pets will be spells where the beast appears for one moment.
Calling it now. I would be surprised if they even let us keep out the pets for more than the duration of the spell.

I will be incredibly sad if this is the case. IDEALLY they use something like the Chocobo Companion system, but you're probably right and my mood has been preemptively ruined.