We're working on the next version of AppInsight for Active Directory, and we have some questions for you about "Trusts". Specifically,
Looking forward to seeing everyone's input on this! 
Over the course of many moons, acquisitions, and regulatory compliance efforts, our environment has grown from two forests (internal and DMZ) to six. It is now in the process of being consolidated back down to two* forests.
*Just in time for us to begin evaluating Microsoft's relatively new references for a "Enhanced Security Administrative Environment" (ESAE), which is otherwise known as a "Red Forest." So who knows, maybe three, but don't tell anyone I work with yet. 
Some of the important attributes about trusts may be obvious to some, but I'll list everything that comes to mind:
With multiple forests and different kinds of trusts, having a good map or diagram definitely helps.
Beyond scope: At the intersection of SAM, AppInsight, ARM, and SEIM, it would be neat to see additional insights about SID history usage and cross-forest SID translation.
Thanks for the very complete response! 
What would also be cool is a map-view of the trust relationships and the forest(s).
Something like this (I'm not the GUI designer in our Company 
) if you hover over the map the basic information will be shown.:
