Do you think an info / inspector style panel for the in-focus item would be useful?
This is something I find myself wishing for often. Similar to apps like OmniFocus on the Mac where each item has its properties and meta-data available in a panel on the right hand side of the page, that can be hidden when not needed. The info panel could allow you to manage the items notes, tags, view creation and modification dates, checklist properties, even eventually custom meta-data and links to other items!
Here is a screenshot from OmniFocus https://www.dropbox.com/s/zrbkjy0jaitt8l9/inspector-panel.png?dl=0