I received this request on a russian forum. The indended use is to copy the "Diary" feature of PuntoSwitcher. In case of any crash, you don't lose anything you've typed in any program. Of course this can probably be used to do some spying as well ;)

Fixed in 1.5.4

Released in 1.5.4

You are welcome!;)

Already implemented

Yes, multiple instances of CintaNotes can work with the same notebook. Since CN uses SQLite, all DB interaction is done within a transaction.
I have taken the liberty of converting your points into separate requests:
http://roadmap.cintanotes.com/topic/87250-shortcut-to-run-second-cn-instance-on-the-same-database/
http://roadmap.cintanotes.com/topic/87251-different-titlesicons-for-different-cn-instances/