About issues being related to objects... I spent a number of years as the architect of a commercial process management tool, that had a pretty mature underlying repository. We built a couple of tools that managed issues, changes, faults, test cases, releases, components, etc. In essence everything in our repository should be an object, and with some limitations (that tend to shrink every time you look at them) an object such as an issue should be capable of being linked to any other object, for various reasons: sub-issue (containment), related issue (association), issue related to test case, issue related to change, issue associated with one or more artifacts,, etc. The same is true for changes, faults, glossary items, resources, almost any object.
A model this abstract is more difficult to build, but is ultimately more powerful.
So it would be very useful to be able to attach a list of related objects to many objects, and navigate to an object with a double-click.