We've been confusing the issues for what gets paid for, how that's determined, and who does the paying. Several health care systems that are attractive to me a use a fee for service model, which you endorse. The Canadians for instance have a singe payer, the government. What gets covered and how much the government will pay for that coverage is negotiated between the government and providers. The quality of the care provided is outstanding by any standard, and superior to ours by many. We have a similar system, called Medicare. The critical difference is that until now there have been few limits on what Medicare will pay for. Inevitably, lots of care of dubious value is supported, to the benefit of no one but those who provide it.
I share your qualms about IPAB, the law of unintended consequences and the rigidity of bureaucracies that inevitably care more about themselves and their own culture than those they have supposedly been created to serve. And with Congress involved, the potential for meddling in the service of innumerable lobbyists seeking favorable treatment for their drug, procedure, or disease is limitless. IPAB is really just a vehicle for rationing, which I favor. That it's rationing on the sly doesn't bother me in the slightest. A "free market" system also rations based on one's ability to pay, an arrangement that I find indefensible on both moral and public policy grounds. Delayed care is inevitably more expensive and less effective. A middle ground, with basic health care provided for all, and the option for the rich like you and me to buy whatever else we want, would be acceptable. After all, that's the American way.