So how hard is it to replace Obamacare? In actual fact, replacing Obamacare with a free market in health care is absurdly trivial. All that needs to be done is eliminate each and every mandate imposed by Obamacare. Done.
What about folks with "pre-existing" conditions? Such folks can enter a high-risk insurance pool that is partially subsidized. (That's how auto insurance is handled). Folks who choose not to get health care insurance at all can take a number and wait their turn. At some point, folks have to show enough initiative to do something. Absent that, it is unlikely the health care system can do them much good anyway.
How about insurance companies dropping coverage? Insurance companies can sell two kinds of policies -- those that can drop coverage and those that can't. Obviously, these kinds of policies will have different prices, as they should. If you want a policy that cannot drop coverage, then pay for it.
Meanwhile, folks should buy whatever insurance policies that they want to buy. Period. There should be no minimum requirements for health care insurance, which is the case with auto insurance (except for liability coverage for which there is no analogue in health care insurance).
Should a hospital be required to take on anyone who comes in the door? Absolutely not, A private hospital should be run on profitable basis. The hospital should decide on its own whether or not to take someone in who cannot pay and the hospital and staff should not be liable for any mistakes or problems with the care provided to non-paying patients.
If you want hospitals to take in all comers, then build hospitals for that specific purpose. Don't destroy private hospitals by insisting that they take all comers.
Meanwhile medicare should be replaced by health insurance vouchers and get the government out of that business as well.
If you want an industry to provide quality and low prices, put the industry in a free market. If you want incompetence, corruption, poor service and high prices, turn it over to the government.