I do not ship internationally and I have non US payments blocked

So after two BINS, I have a buyer who cannot pay for their items because they have a FL address but a Canadian bank.

I read the other thread about this, but I still do not understand how they were even able to buy my items if I have non US payments blocked. Or does ebay just look at the address?

I guess my main question is, if I lift the block, will I then be shipping to a confirmed address in FL, or will their confirmed address be in Canada and the FL address will be the non confirmed one?

It's totally your choice. The Cdn buyer will be registered in Canada, but will have a non-US paypal account and therefore cannot pay. I usually ship to them, as they are able to specify a US address in paypal when they make the payment. Probably spending the winter in Florida....

As long as they request the US shipping address, I unblock, ship and then reset the block.

Send them a message, and make sure that they are there long enough to receive the item, just in case, plus you will get confirmation in writing to ship to the US address.