well since you are already using focus

why not use macro's like these on all toons
/cast [target=focustarget]lightning bolt

this will cast LB on the target of your focus.
this also makes it easier you you switch screens, add a macro on F1 that does /focus 'char1', on F2 make /focus 'char2' etc.
switch screen, press the right focus macro, and all the spells will continue to work