General questions about classes

[Ayuhra]

Hello everyone, new here so greetings to you all.
I have this question at the back of my mind. I am not so young player anymore,
and moves and reactions are not so fast. I was wondering does every class need
to press buttons crazy fast to perform they openers or later rotation ? I know that for normal gameplay this is not relevant, but for high end content ( which i would like to play ) is kinda mandatory to perform at your best. Bit worried, and here my question. Does some classes play slower, or can you overcome this by lots of learning and beating to a pulp those poor dummies to play class what you want ?
Thanks in advance for any pointers, and sorry if some grammar mistakes, not my native language

Speaking as someone with similar issues, here's my finding:

DANCER has the fewest buttons to press if the number of buttons is an issue. The rotation, however, is fast and you need to press quickly. But being able to move around makes it decently easy to recover from mistakes.

BLACK MAGE has more buttons than Dancer but presses them less often and they have the slowest rotation of all dps. The rotation is fluid and intuitive and not very hard. Difficulty in Black Mage comes from knowing encounters well enough to actually be able to plant yourself and do the rotation properly. This makes it arguably the hardest job in the game from an execution standpoint but that difficulty at least isn't in tangling your fingers up.

For something between the two check out RED MAGE. Less fast than Dancer, more fast and more forgiving than Black Mage.

(edit: Also, for me my reaction time playing fast classes improves with a controller, that might be something to check out.)