Your comments

This would give us the best password manager ever.

Looking forward to this one!
Search would expand notes where it found matches, right?
What about "expand/collapse all" commands?

By the way, this can be gereralized (yes I love doing that) to remembering amount of showed lines for individual notes. This amount could be easily set up by pressing mouse on note border and dragging.
Good point!

If user is writing something, and the note got auto-saved in the bin, further 2 actions possible: user cancels note, and it remains in the bin as in "cancel" scenario, or confirms it with OK and there's no point to store it in bin (or "draft") anymore.

I see no more problems, thanks.

1. User deletes a note. No confirmation, note goes to Recycle Bin.
2. User cancels a New Note. Note gets saved in.. ok, Recycle Bin.

Number 3 was just an idea about GMail-like drafts and auto-save behavior, that would make drafts of new notes that are being edited longer than X seconds. In this case drafts should no go to Recycle Bin since user doesn't intend to throw something away.

So I was just referencing possible, yet not existing feature and could be wrong in that.
What about "backup now" action?
Will attached files be stored in the DB or just in some folder (making it viewable without CN)?

What about exporting attachments ("save file..." action)?
Ctrl, shift and alt clicks should also be possible then.

This feature is related to:
How would you identify notes?

What if we rename linked note?

What if we delete linked note and the link gets broken?
Good idea.

Some questions here.

1. Where should tags be clickable: in notes preview list or in note editing window? (or maybe both?)

2. How is "Rename tag" action handled?

3. What action is tag-link clicking equal to? Just clicking on the tag bar, ctrl+clicking, shift+clicking or alt+clicking?

4. What are semantics of tag-link clicking?

If it's "Show me all notes with this tag", this is actually a search query and can be generalized to "Show me all notes matching condition", where tag-links could be formulas with set operations:
"|" is union (or), "&" is intersection (and), "\" is complement (substraction)
for example [tag:(foo | bar) \ goo] would give same effect as if we shift+click "foo" and "bar" tags, and then alt+click "goo" tag.

Another option is making simple tag-links (no formulas), but let user click them with ctrl, shift or alt modifiers to change his search query.

This feature is related to: