after deciding i needed more research and not knowing where to begin i looked at the Unity Learn pages and read everything I could find on the Animator component and Mecanim. i noticed one particular video from a previous Unify (sp?) conference where an entire presentation was given about how to simplify the state machine flowcharts in Mecanim with sub-state machines and blendtrees. the speaker also mentioned how it’s okay to put logic in Mecanim as long as it’s pertaining to animation control.
looking at the complexity of the charts used in a full scale project must have helped, or at least convinced me Mecanim was capable of accomplishing my need. i’m still not sure if the most elegant way to accomplish the task, but after much mucking about, it’s almost working.
refining the flowcharts a bit seemed to do the trick, as well as keying raycasting in the canvas group off/on. it may be possible to use one animator controller and a sub state machine for the sub panels of the menu, or perhaps triggers /w built-in onclick events instead of transitioning with boolean animation parameters called from code is a more solid approach? overall, i’m not sure how to proceed.