if you hit

ctrl-enter

while the typing cursor is over a the text of a #tag, it should make the note, unless there's something interfering with the binding - not sure if that's automatic enough for your use case. As for visualizing the notes with the tag, running the show note graph command from the page corresponding with the tag should show you that by default - the toggle between showing the full graph and showing the local graph around the currently opened note should be in the top right of the graph UI