Good points but important to point out that driving down costs may not be a net negative. From Buffett's comments in the video he seems to be indicating that business are more likely to make investment and hiring decisions on the basis of high and ever-increasing health coverage costs than a change in corporate tax.

Capping or reducing healthcare cost as a % of GDP may help many other sectors to expand. On this basis politicians should first try to get the support of corporations to reduce their insurance costs, and try to change the argument - sustainable healthcare for all. This kind of corporate backing would counter the inevitable lobbying of pharma/medical corporations who will put their resources into countering any legislation that reduces their profit margins.