A limited set of actions can assigned via macro commands. Incompatible actions are ommited from the generated macro. Also note that Macros are limited to 15 lines each.
/micon Shirk /merror off /ac Shirk<t> /ac Royal Guard
Something that works for me and keeps single target and aoe abilities grouped together in a way that flows for my brain
No new buttons. Maybe place Reign of Beasts on Shift+E if it feels bad as a combo to Bloodfest.
Trajectory will replace Rough Divide.
Bun Boss Gunbreaker modified for my needs.