I recommended paladin because it is (for me) the most intuitive tank to play. The abilities do grow in number but I don't feel stress from clicking on all the buttons.
With that said, you are totally right about warriors. They would be fantastic for someone with trouble with their hands.
Kallistra, and the much missed Selli, recommended that the OP try out different classes and play the one they liked the most. I think that's the best advice, really.
BUT...
In the interest of helping the OP, I'll list what jobs to avoid for now.
Monk. Now, I love monk. It's simple to play and does good damage. However, it requires a lot of button pushing.
Dragoon. The same. I adore the job and am leveling it on an alt. Again, easy to play but requires a lot of button pushing.
Black Mage. This one is borderline. It has an easy rotation but you have to be really good at picking where you should stand. This will frustrate new players. But, it is a fun class.
Dancer. Super fun, but dear goddess... your fingers will cry.
Machinist. The same as dancer. Love this job but it is busy as hell.
Samurai: Nice class. Try something else first to build up your speed and confidence.