Macros shouldn't be used for most combat for several reasons.
- They slow you down because they block the action queue system. Unmacroed actions can be pressed up to a second in advance, and will execute when the current action is finished. Macros must be activated after the current action finishes.
- They slow you down because waits can only be whole seconds. If you try to wait partial seconds, the system rounds to a whole number. If your GCD is 2.1s long, you have to use a <wait.3> to make a macro execute actions in sequence. This means you'll only take 70% as many actions as you could. This is a huge loss.
- If a sequence is interrupted, you need the next action somewhere on your bar anyway, since you can't start from the middle of a macro.
The exceptions are macros targeting secondary targets for buffs, heals, and raises, which allow you to do things like raise "whoever is dead" without specifically targeting them, or quickly manashifting a healer without changing targets; and macros for ground target AoEs, which will center them on the designated target and are faster than pressing the button, placing the cursor, then pressing the button again.
tl;dr: don't use macros for combat actions.