Also, all your "target=focus" spots can be replaced with "@focus". This works for all instances of "target=", replace that with "@".

If your macro fits in 255 chars as is, there's no need / benefit to shortening them. "Optimization" implies that your shorthand is improving the macros in some way, which is not the case here. In fact, some of the macro shorthand actually obfuscates the function of the macro, which can make it harder to remember exactly what the macro does, say after an extended break from the game, or in the case of a rarely-played alt.

As a side note.... great article stony... but the wealth contained in the comment on this one is where the dessert of the macro feast is at... :)

I find the shorter versions much easier to read myself

Actually, in the case of the modifier macros, there is a very good reason to change them. Right now,

/cast [nomodifier] Fire Nova; [modifier:alt] Magma Totem

Will cast Magma if alt is held and Fire Nova ONLY when no other modifier is held. That means that if you are accidently pressing shift or ctrl this macro (which may be behaviour you want, but probably not) will do nothing. It will also cause a big problem if you are putting this on an actionbar that is bound to [Shift]+Number (for example, I use the secondary action bar above the standard one with it bound to Shift+` to Shift+9) In this case, Fire nova is impossible to cast with this macro unless you click on it with the mouse.

Additionally if you mouse over it, it will only show the name of the macro, not the spell details (which you may want to remind yourself of for some reason).

#showtooltip
/cast [mod:alt] Magma Totem; Fire Nova

This, as Rodalpho suggested, would be a marked improvement since it would not cause those issues.