If I 'Add' an entry accidentally, can I immediately "click back" to correct it? Especially if I'm not sure what the accident was.

Hello Turnerpaul, 

Welcome to the Community page, 

Yes you can edit anything you need to in QuickBooks at any time, if it helps you can click on the magnifying glass top right hand corner and it shows you the latest things that have been done in QuickBooks. 

If you are meaning adding from the bank feed, you can undo this from the reviewed tab this will then move it back for you to re add or match up again.