The kick that lands through your own cast
The reasons mages lose interrupts are (1) they were mid-cast and (2) they were aimed at the wrong caster. This bind kills both causes: stopcasting first, then kick whoever your cursor is on, with the focus caster available on shift:
#showtooltip/stopcasting/cast [mod:shift,@focus,harm,nodead] Counterspell; [@mouseover,harm,nodead] Counterspell; [harm] Counterspell
Arena players hold shift for their focus caster; everyone else just hovers and kicks. The pattern is the focus page's gift to mages.
The polymorph modifier
One key, two poly targets: shift for the focus (the kill target peels off), plain press for the current target:
#showtooltip/cast [mod:shift,@focus,harm,nodead] Polymorph; [harm] Polymorph
The escape key
Blink deserves the least decoration of any bind in the game: one line, one intent, never a chain that can eat it:
#showtooltip/cast Blink
The frost nova embrace
The crowd-control bind for the ring on the floor: nova your current target when it is crowded, keep it simple otherwise:
#showtooltip/cast [mod:shift,@player] Cone of Cold; Frost Nova
Shift throws the cone out of melee range; plain press novas the crowd. Both gates are from the conditionals page, and neither needs a proc, which is the whole mage macro lesson: your macro-relevant tools are the deterministic ones. Everything else lives in theaddon half.