Im not in game atm but from what I remember you do have a few buttons to press, none of them super fast as it usually goes from hard casting to instant cast, until you fill your ultimate ability, the part that can be considered fast is yes the melee part but I think you only have like five buttons to press, dash, use three abilities and jump back (if you want to) and then ultimate, rinse repeat.
You of course have time to press all those buttons at your will.
Summoner is very easy to remember and play now, but unfortunately its a fast class, rarely any hard casts at max levels.
Another thing I can suggest is healing because the actual damage rotation is pretty much one DOT (damage over time) and then one button spam until someone needs healing which can again be done easily if the party knows what they are doing but you will have to react and adjust to whichever party you get so it will get stressful, I don’t call healing babysitting for nothing xD.
If you do try healing do not go for AST, pick WHM.
I suggest reading up on this website:
https://www.icy-veins.com/ffxiv/red-...ners-abilities
They explain everything very throughly.
Besides public content, ffxiv has a lot of content where you don’t have to feel pressured, exploration, crafting, gathering, questing, you can even unsynchronise old dungeons and trials until you feel comfortable and experiment/learn your classes, take your time and don’t pressure yourself, gaming is supposed to be fun and relaxing.