mainly I wanted to know, if it's ok, that on can add notes and attachments to tags. This came to me as a surprise. So I assumend that 'Sort' was meant for the thoughts that have this tag, and not for the tag's attachments.
I understand, that, conceputally, you treat tags (similar to types) just as a special kind of thought. You even show a tooltip saying 'Tag Thought'.
But then: If you try the action 'Edit > Add <tag> to Selection', nothing happens. With types, this is possible. So this action should either be disabled or executed.
With types, one can associate a type with a calendar event. Why is this not possible with tags?
And maybe, the wording of the menu items and the tooltips need some work if a tag is the active thought. Here I would follow Steve Krug's advice "Don't make me think". (Steve Krug, Don't Make Me Think!, New Riders). I get confused, when I see a tag as the active thought, but read 'thought' in the tooltips and menu items and have wonder, which actions apply.