Dual Boxing Issues...

I'm not a noob at dual boxing as I have done alot in the past... just not in WoW.

Physically:
2x PC, Monitor, 1Gb, reasonable GPUs, keyboard/mouse, N52.

Software:
Synergy and Multibox

Sadly none of the hardware is the best, I just can't afford the good stuff. :(

So issues:

When I follow on my alt (Mugnin (main is Hugnin)) the actual follow doesn't start until I release the key.
[code:1]/follow Hugnin[/code:1]
So even though I press the follow macro, through multibox, when ever I walk forwards (key is W) if a fail to release I get out of sync. Anyway round this?

Currently I'm learning the art using hunters, mainly as I have a high level hunter on another server so I know how to play one, eventually I'll swap to 'Locks as I like them too. Currently I have autoshot bound on my main to key 1. On the Alt key 1 is:[code:1]/assist Hugnin
/cast Auto Shot[/code:1] That works okay though if I'm out of range it messes up. So is there a macro I can do so that first press of the key activates auto shot, but any subsequent presses don't? I wouldn't be able to switch it off true (maybe with ctrl/alt/etc).

Anoither issue I'm having is that the alt will not fire the serpent sting. I have tried with a macro:[code:1]/assist Hugnin
/cast Serpent Sting[/code:1]
And also just as a normal keybind to the spell. Neither work. Though I can physically press the key on the 2nd N52 to get the effect. The key works when I try it outside of WoW or in the keybinding thing.

So in other words I need help with macros :(