Queue tag, email addresses, and ticket flow - Explanation?

Our service department is looking to restructure its queues and email addresses to improve our customer experience. In their initial draft, I don’t see anything too problematic. However, one of the things they want to do is use a single email address for all correspondence. I’ve been looking online for documentation on the queue tags but I haven’t found anything useful. This is my understanding:

If an email arrives in a queue in box with no queue tag, then the default response is to create a ticket. If the same email address is used across multiple queues, but a ticket can only be created in one of them what would happen?

For existing tickets, if the ticket was moved from queue A to queue B the system will recognize the ticket number being in a new queue and update the correct ticket. Is this the standard behavior?

To reduce the number of mailboxes we have, we are looking to move to IMAP and use folders to move separate emails and have wsgetmail leverage those folders to put mail in the correct queues. Are there any gotchas with this solution?