Medicaid Budget 2012
Total Money Given to Charities in 2009
So if you collected every penny that people gave to Charities you would still be dramatically short. Not to mention I doubt that folks would be happy about all their money going to one place. Regardless that sounds a lot like taxation.
Also these collections are spread out over thousands of different groups. How anyone would imagine collecting this to be used as some sort of functional block? It would be akin to mass chaos.
In regards to your other point...
...the old argument. If we only went back to the good ol' days when you could pay a doctor with eggs or a pie, everything would be fine and dandy.
Allow me to throw some facts at you.
1935- about 55 per 1000 births
Now- about 7 per 1000 births
A dramatic accomplishment that is in no small part to providing poor folks access to care.
Now people made up for it by having about twice as many babies in those days. Of course this tied up women to essentially child production and rearing.
Finally to your arguments about how charities/private firms are more efficient at delivering care to patients than the goverment is almost like a theological argument difficult to argue.
But I will leave you with this.
The US has socialized universal government run healthcare system. It is the VA.
The RAND corporation did a study on comparing the costs of delivering healthcare in the VA vs. Private.
THE VA WAS CHEAPER!