A: Yes, of course. But why "finally"? :) We've had this functionality for about five years now :)

Absolutely every sent or planned campaign is also a template for a new campaign.
You need to go to the Campaign History, go to the specific Campaign you are interested in and then proceed as shown in the screenshot - 🔗https://prnt.sc/dcIhMFsLboZ5🔗

You can copy a campaign for your current website or for any other website that is added to your account.