It can only be reversed if the transaction fee is low meaning once the transaction fee isn't low the transaction can't be undone we are on the same page.
Not really.
Low fee or not, an
unconfirmed transaction can be double spent.
Each block is confirmed averagely every ten minutes, so there is always a gap between when a transaction is broadcasted, verified and when it gets its first confirmation (not necessarily ten minutes).
A transaction is not complete until it gets at least 1 confirmation, for much higher amounts waits for 3 confirmations, ideally.
Automatic I meant in my context was no third party intermediaries stand as bridge during the transaction
True, there's no third party intermediary, only nodes and miners who help secure the network.
P.S, here's a link to a snippet on how to
Quote a post. I understand it can be a bit difficult to understand at first, but practicing and checking how other users does it would help you perfect it.