Splutty-
There were two versions of key spammers- one where you hold it down and as long as you hold it down it spams, and the other where you toggle it on and off. Which version is yours? Thinking about keying it in, might be faster to have the dead man switch version which turns off on release. Otherwise you have to toggle it on, toggle it off, hit another ability etc.
Greyed-
They used to have a priority macro. I remember making them for my warrior with the default macro system. I put the highest priority stuff up top, and the lowest at the bottom. Worked great until Blizzard changed the rules. What GSE does is bring that back. There is no priority system in the actual macro system right now.
So for my warlock I did something like this for the basic Dot-em-up macro
#show
/castsequence reset=3/tar agony, haunt, corruption
Since I have perma corruption, the need to refresh it is low, particularly if it is applied by Seed of Corruption. So this kind of macro would try to dot it up.
The problem here though is agony and corruption are not on CDs, but Haunt is. So if you get to the sequence part where haunt is going to go, and it is on CD, the sequence just pauses there and hangs.
Again this is where GSE comes to the rescue. You can set it up in a top down sequence, and if it is not up, GSE goes to the next one. If you want it to hang on something on CD, then you can still put in the sequences.
So in the examples I had where you mix and match top down and castsequence in GSE, you can do the kind of thing you describe. Players found a way to do this.
All I really want to do is remove the moronic anytime stuff to simple rotations.