I've been a long time mouseover macro user. I prefer the efficiency of just placing my mouse over the intended target rather than having to click the target to cast my spell. Unfortunately, too many times in FFXIV:ARR have i noticed that sometimes when I have my mouse hovering over a party members name and I hit my "cure" macro the spell is randomly cast on myself instead of my intended target thatmy mouse is hovering over. This has now caused at least 2 wipes because my heal has landed on myself (since you can't tell who the spell is aimed towards) rather than the party tank.

To top it off, my macro looks like the following:
/macroicon "Cure"
/ac "Cure" <mo>
/ac "Cure" <t>
/ac "Cure" <f>
/ac "Cure" <tt>

With the above macro, even if I have my intended target selected and my mouse over that target, the spell still randomly lands on myself for some reason. I'll try to see if I can recreate the problem outside of battle.