1. You can use NostrGram single column. Just click the Twitter icon under the Note Editor at the top of the page.
2. You can show the relays each note was seen on below the note. It's an optional note in Settings ⚙️ under Advanced Settings toward the bottom.
3. You can see the JSON structure of any note event by clicking the ellipsis (...) in the action icon list of any note and choosing "Note Info".