Regarding issues 4 and 5, I had this happen to me recently when a service tried to charge my card 1 pence (GBP) to check the validity of my card. The bank said

Regarding issues 4 and 5, I had this happen to me recently when a service tried to charge my card 1 pence (GBP) to check the validity of my card. The bank said they fail these transactions on fraud protection, as many fraudsters will try a very small charge first to see if a card works.