I would check with the State you moved to when you're applying for your new state tags. They should be able to tell you what to do with Florida's tags. Hope this helps!
Yes but some states ask you for them before you get theirs so before you leave call and check with them
I'm not sure about mailing them. You can call and ask, but I know you can physically turn them in at the office. Make sure you get proof that you surrendered the tag in case you ever need proof for whatever reason.
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