It's true they are being made by completely different developers and it's completely different code. Many of the differences are just to account for reducing hassle for mobile users, who may not have a lot of time to play due to using it while on a train and needing to get off at the next stop.

However, I am sure they will do things that they have struggled to achieve in the main game, because I genuinly don't think other developers would have some of these struggles.

I don't know what the movement system is, but there are a lot of options here (Standard vs Legacy, reducing movement physics, etc).

Casters don't have autos because you don't auto while casting. Ranged Physical DPS have ranged autos because they don't cast.

Over time, casters have had reduced cast times (Red Mage and Healers) or removed cast times (Summoner), but all of that is really just to allow for "slide casting". I doubt the developers really care about auto attacks on them and their potencies are meant to account for the lack of autos.