Re: As a concept
"Accredited battery sharing clauses will make refuelling with new batteries mandatory and as profitable as the market will allow."
Swapping batteries is technically feasible, the problem is that it won't work if the asset ownership transfers at every battery change - think of the nature of the second hand car market, and you'll see that you'd have perennial problems of companies and car owners trying to swap duff battery packs onto unsuspecting mugs, and seeking only to ever take back prime condition packs.
A battery leasing model might be the way forward. The lease company owns the asset and provides it fully charged, the customer pays for energy metered out of the battery plus the costs of swapping and asset depreciation. Battery ageing is a minimal problem because as a driver you're never landed with a duff battery that you own, and because the battery leasing company can monitor the asset condition and life expectancy of every battery, withdrawing packs as they age.
The problems with this are that there will be limited competition in the battery leasing market. Even if you have multiple leasors, a battery swap station will only carry a few brands. It will also be a natural business evolution for business leasing (ie financial services) companies, so given the inherently crooked nature of financial services I would expect unfair T&C, penalties for "exiting" one leasing scheme to join another, punitive costs for wear and tear or accident damage, restrictions on self charging, and anything else that the bankers can invent to line their pocket at the expense of the consumer.
However, given the limitations and losses in battery EVs, I can't help concluding that EVs will remain a metropolitan solution. A more practical universal "low emissions" transport solution would be power-to-gas systems using H2 dissociation and methanation to produce methane, which most spark ignition engines could easily run on. End to end efficiency is poor, but that's true of EV's outside of the laboratory, but methane powered transport is fully compatible with anerobic digestion of degradable wastes, with fossil natural gas solution, and potential future resources like gas hydrates.