Thanks for taking the time to take and look and leave your feedback. This is really important to us 🙂
Straight to your points. We’re already examining the option of making authentication optional in the near future. The benefit of being logged in is that you can easily access your tabs on all devices as you can also use our web app as an alternative to access instatab.
Tab deletion is currently not possible, only archiving. The idea was that it multiple people are on the same tab it may be confusing when you delete it and it disappears for everyone. Archiving is individual to the user. That said, we’ve received similar feedback before and will be adding tab deletion in upcoming updates as well.