I never use 7-0 keys, I use my mouse for anything I can't keybind on the 7-0 abilities to letters QERT FG ZXCV. I also keybind my mouse wheel (pressing it) to sprint (I'm a healer, comes in handy while I'm running around) so when I'm moving around I can still use abilities around the WASD keys that are within reach.

You get used to it. It was hard at first but once you know your keyboard layout, you do it without thinking.

Helps to keybind similar actions to the same letters through the jobs (Medica II on T, Aspected Helios on T, Sacred Soil on Q, Collective on Q, Medica on R, Succor on R, Helios on R, Addlo on 3, Aspected Benefit on 3, Regen on 3, Esunas (sch, ast and whm versions) on 5, Aetherflow / Shroud / whatever the AST one is on X.) it gets to be muscle memory then no matter what job you're on.