Is there a way to view mates by some kind of "priority" or "hierarchy"; by what the mates are attached to?  

I don't think either of these descriptions is ideal, but I don't know a better word to describe this functionality.

IE: mates to the Assembly "main / top level" planes could be prioritized, or tagged, or differentiated, or rated higher than mates to other parts or sub assemblies, sub part planes, etc etc

This functionality would help identify which mates drive the positioning of a part; or group of parts. 

I am repairing some old assemblies (large, many sub assemblies stacked into each other, with random mates, no consistency in what is used for mating between sub assemblies...), with multiple configurations driven by multiple mates that change (get turned on/ off) between configurations. Mates have been set up in chains so that one item is mated to another item, to another item, to another and that is mated to an assembly reference plane or fixed, etc. Bad practice I know...but there you go. Surprise surprise now mostly broken, with parts levitating off in all directions.....

I don't really have time to rebuild all the mates, but it would be handy to have some kind of insight into what takes priority, what the mate order or positioning "cascade" sequence is.

It would actually be awesome to be able to click on a single part, and see all the mates or restraints (Planes, sketches, "fix" states, etc)  that link that part's position back to the assembly origin....

Any thoughts or suggestions would be appreciated. Cheers-