Problem is the space available for all these attachments...unless the puppet's capacity is expanded most stuff remains very hard to be worth using.
I really hope Square realise this, and include an expansion - whether this be through an update to the job, or through a merit like blue mages receive. I'd be thrilled if this was includes in our 99 merits.
As for attachments, well, eh. I'd have to echo your sentiments, some of the already existing attachments should be innate - Shield mastery, counter, double attack to name a few. We have a finite number of slots to work with, and some of those job ability/trait attachments are non-negotiable.
As for creating attachments that are meant to emulate certain jobs I fail to see how that'll improve things. Many people draw analogues to pld and Valor, but without a native mp pool that can't be recreated. Most other slots on the mage jobs are accounted for. Barrage turbine is a great example of an attachment done right, though it does eliminate wind maneuvers, which messes with haste and can cause the wrong ws to go off.
I know that our mage frames got quite the buff recently, and for that I am thankful, but there are some more changes I would like to see implemented. Damage gauge + Optic Fiber I feel is broken, never do I need a cure at 80% hp, often this will create scenarios where my mp will burn at stupidly fast rates. I'd like to see Damage gauge either removed or changed to grant an afflatus: solace type effect and the curing behaviour to be innate to the frame. Furthermore, I would like to see Soulsoother cast cure 4, instead of just 5 and 6. With the changes to cure 4, and vivi-valve + 1 LM it can easily cure for 600, which my dumb little cure-auto often cure 5s me for.
Other adjustments I'd like to see include: More job ability attachments, allow Barrage turbine to consume only 1 Wind maneuvre, innate job traits like counter, double attack etc (That are further enhanced by the use of coiler etc), Auto acc buff. Reworking of harlequin.
Wishful thinking: The relegation of MP to the head slot, Auto-refresh on the red head, Cure potency + on the whm head, MAB on the BLM head, New PLD-Esque head that enables self cures and Auto-buffs.
Either make animators do something, allow us to equip ammo with them or remove them entirely. Rng head: Snapshot Valor: already seems to gain more native pdt, but perhaps Attack boost.