I would love the option to hide inactive Attributes (Appeals, Notes, Events, and Actions, too, actually) when looking at records. Sort of how in some places there is the option to show/hide inactive entries in tables, but make it a user setting for records - that way, I maybe won't feel so much of this compulsive need to cleanout old Attributes (etc.) so that I can see at-a-glance information when viewing a record. Would love to see it as a user setting or a button like the "Attribute Category" sort option, but that sticks (currently, using that option means you must select it for every record that you open).
Not obsessively cleaning out your old attibutes just keeps junk holding up space in your database. I would not want this.
the sort option should be a separate suggestion - then I would vote for it.