nope since you sugestion implique get new skills so all the new space will be used and you won't really have space to put the same consolidated combo the number of times you want to in a confortable way, it can lead to visual confusion since you will have a lot buttons changing the icon constantly and you can't rely really on muscle memory for it since for what? just spam random all you combo buttons, literraly rolling your face over the keyboard, you won't be able to mess around with the rotation so it's making it easy for the sake of making it easy.
thats relative, while i miss certain skills is not annoying for all, it's only annoying if what we get in enchange is useless of literally worse and boring, at the end all you space gain will be used for other stuff and eventually you will find yourself on the same situation where you have to remove skills to get new ones so you wont solve anything, just delay 1 expansion meaby 2 the inevitable, you should consider for tome ppl is way more boring spam the same buttom over and over againg compared to dealt with the considerable amount of animations we already have, only DRK and healers iare repetitive for the poor rework but the rest of the jobs are not boring to watch.
both systems use a oversimplified versions of the jobs, on roleplay duty only thancred use the consolidated combo and it's only 1, all of them y'sthola, hien, alphinaud and thancred use a maximun of 4 buttons for everything.
you say multiple times this need to be used to incorporate even more buttons and more mechanics to get more complexity, DPS have enough levels of complexity only tanks are simple and still PLD and GNB are on reasonable level of complexity, we don't really need more complexity and we can archive great levels of complexity with what we have, example HW-SB DRK and pre 4.2 WAR rework, so that point is complety irrelevant, all this just scream i want to do the maximun amount of fancy stuff doing the minimun physical effort for it and almost complety removing the margin of error on a game that is already is easy in so many aspects, it would make it more boring since you wont need more that spam 1-2 buttons to complete stuff and promote laziness.
so yeah it will implique a great amount of manpower implement, develope and balance all what you say at the same time all jobs will requre much more manteinance to secure the amount of mechanics you wanna add on top of what we have and make it work properly at the same time adding new jobs to the game. this last point is more important bcs the combat dev team are only 4 guys, more jobs means less time to properly develop current jobs properly so they want to make everything more simple for the sake of cuantity something if you didn't notice start hapening this expansion.