Diagnols aren't a very good solution, can't you just change the angle of the unit like +5 or -5 depending on a/d and have a/d move the unit as you would with a?
Or I guess better yet to use q/e and for those motions and a/d only for strafing left or right. OR switch that since people would probably use a/d more for turning then they would normally use a straf.
Actually no, if I hold my key down then it keeps casting the spell again and again and again. And with the 8 way thing I was talking about having the W and S as a toggle, so yeah a toggle would be a while loop, but you can have a lot of stuff going on with the sc2 engine then you probably think. =D
I made a 4 way button press via data + triggers (data in the sense that he casts a spell and I use that as an event) and from what I can tell, it doesn't lag any either. The best way I can think of making an 8 way via my method would be to make the W and S a toggle while the A and D are for changing the angle of your unit. I think this wont really be interrupting the nature of moving at all, but it would take some getting used too. I'm thinking there may be a way to reduce the transparency or something similar of the ui that you must keep up via the galaxy editor. Wc3 had custom skins and things for the ui, I'm not positive how they worked, but couldn't someone just replace all the ui with nothing?