When the final payment is due if you have to drop out I assume that you will be refunded the initial payment and your slot given to someone else but it could get complicated.
Either way you would get a refund for this down payment if for some reason you could not complete the order.
There were almost that many posts about taxes and customs and shipping and crap. And all the while a large chunk of us are completely unaffected by any of it. Ignore what you don’t care about and get on with your life.
FWIW, I forgot my email address, so I sent another payment to Neal of 0.01 dollar with BLF-GT number plus the missing email-address. That was my way to solve it, I guess Neal will get it