re: #2

You can edit all of the individual components of a tag (attributes, the tag itself, add new attributes, etc.), but you can't edit/select the entire tag or child tags at once as you can in Firebug.

This can be really powerful, because when you can edit an entire tag including the open/close brackets, you can type in whole new tags or paste in a blob of new HTML.

This bug was the closest I could find: https://bugzilla.mozilla.org/show_bug.cgi?id=777009