payee

The means of blocking is the car that they have sitting in the spot, which presumably they won't move until the payee shows up.

Only one (former) account ever done this, and it was own used when adding a new payee records.

Benefiting the payee is not always productive.

Venmo doesn't post the amount to facebook on the payee's wall, but posts the short text description that the payer who pays the payee writes in venmo when making the payment.

The payee needs to have some kind of uplink (like a mobile phone, amateur radio, or anything).

The payee of federal income and payroll taxes is the federal government, not either the employee or the employer.

The worry is about the companies that want to control both ends, like Coinbase, not payment processors in general that simply take care of accepting BTC on behalf of the payee.

The Payee will be reasonably motivated to add their CC to retrieve the funds.

Treat the account number like a password and have the payee enter it twice.

To prevent double-spending, the payer and payee first set up a 2-of-2 multisig, so all transactions must be signed by both parties.

The concept exists, but it requires the payee to actually set that up.

Unanswered in the paper is a look at the wallet implementations; can I expect wallets to correctly report the balance in a payee's wallet, if they have outstanding contracts?

I think you mean "payer" rather than "payee".

In every country I've lived in, cheques are not only universally hated by landlords and tenants, but all banks offer recurring payments available online (no matter whether the payee is "in the network", you just need the account number and some other piece of data depending on the country).

Yes - the Singapore system uses an offline "signing" physical dongle, in which you enter the account that you would like to use, click "sign", and then enter that information into the website, when you wish to add a new payee.