I'm not so sure that these are abuse. For instance, (2) is effectively an escrow service, hotels and a few other types of service use this quite effectively. I

I'm not so sure that these are abuse. For instance, (2) is effectively an escrow service, hotels and a few other types of service use this quite effectively. I honestly wish restaurants would also just auth an extra 20% on my purchase in escrow and settle the actual tip amount later, and similarly bar tabs. In (3) its also sort of an escrow service, but not really. Similarly, this is why merchant processors are required for a lot of companies to do business over credit networks. They too hold money for some N days before it is released to a merchant (after clearing) - as escrow to the card issuers in the case of chargebacks and other fraud.