What I would like is a command that removes that annoying red text when your using a skill on a target that it can't be used on... on my healer classes I have the following basic macro (slightly expanded on ingame) for all my DPS skills

/ac [NAME] <t>
/ac [NAME] <tt>

This first checks to attack my target, and if it cant do that it moves to the next line and then attacks my targets target (I like to stay ontop of my tank). I can't attack a party member, so a red messege onscreen (it also does it in the chat log but that has a command to remove it (/merror off)) telling me it is an invalid target... and because I spam the skill to make sure its queue'd up, that red text is on my screen 100% of the fight... while DPSing at least. Wish /merror off removed the onscreen warnings too.

Other than that I got nothing... macros are for displaying skill cooldowns, repeating quotes, removing your AST buffs midcast without right clicking them, and silly stuff as far as I am concerned.