I think it's a bad idea to macro in target icons to abilities. There are times when it's nice to be able to use shield lob mid combat like if there's a loose mob or if you need to get out of an AoE but still feel a need to attack the target. Instead I just put marks on F2 through F5 and a mouseover macro bound to each key, hidden from view. Marking the group that way takes but a split second more, and it's much cleaner overall.