Are we currently spending double on healthcare compared to 30 or so countries who more or less provide healthcare for all ?
Compared to the countries that offer universal health care, the U.S. is spending more and getting less overall. By Some estimates, the U.S. is spending twice as much as some of the other nations.
If we do nothing different should we expect the same results ?
Yes, that is usually the case when you don't change anything.
If we add medicare for all who want it to existing costs wont our overall costs go up ?
Actually, total spending on healthcare may go down, as an ounce of prevention can be worth a pound of cure. Seeing a doctor right away for a problem may be much cheaper than having surgery later on.
If we go the way of all other countries why would our costs not compare with theirs?
If we had a similar situation with other countries, the costs and benefits would be similar to those other countries.
Why do we say we are going to take away peoples coverage who are happy with it...Are they now going to have superoir coverage which cant be cancelled with prescriptions covered ?
Some people, such as Union Members, got good healthcare packages as part of their collective bargaining agreements. Some of them worry that a universal healthcare package, such as Medicare for All, may not offer them the same benefits as the healthcare package that they currently have. They worry that whatever universal healthcare package that replaces their package, such as Medicare for All will not cover the same things and will end up costing them more because now they will be responsible for anything not covered under Medicare for All.
Note that you seem to be talking about both Medicare for All and Medicare for all who want it. Medicare for All is basically a universal healthcare package that would remove private companies from providing standard healthcare coverage and have the government do that instead. Medicare for all who wants it is basically expanded Obamacare, and would allow private insurance to continue.