With a strictly free-market system, a hardworking, self-employed person with a pre-existing condition won't be able to buy insurance even if it is opened up across state lines. I don't see anything in your proposals that won't leave that hard working, self-employed person still stuck with getting less health care than your typical illegal alien or welfare leech.
Sure, charitable groups could help, if you want to turn people into beggars, pleading for mercy from charitable groups.
The point of these changes is that medical care would cost only about 10% of what it does now! We would have small practice doctors again, instead of HMOs or enormous group practices. Insurance would only be needed for actual catastrophic events, not for EVERY medical encounter. Insurance would be affordable too. With a lot more competition in insurance, there would be policies or companies that would cover pre-existing conditions. AND, if we stopped tying health insurance to employment, everyone who wanted to could get health insurance and keep the same policy for life. Add reforming litigation laws to the list ;-)
As far as Canada, if their single payer plan is so great, why do so many Canadians come to the USA when they seriously need something done? Because equipment shortages and long wait times for any procedure make it preferable to come here and pay for it yourself...