First off, let me say that this is going in the right direction. This post of focused on the general development UX.
I do not like how the query to perform table updates is added, it is non-intuitive. You have to make a column editable and then the Save Changes Add-on shows up. Saving a change more properly fits with the rest of the event handlers - it does not logically fit with add-ons.
The tick you use to identify an editable field needs a tweak. It looks like the lead on the pencil in the Tag icon and kinds hides in Date icon.
Honestly I though I had a few more, but have been won over by a couple others that I did not like at first.