2. I think it's ridiculous to invade people's private lives and make them pay for being overweight and in this country, such a measure would (thankfully), never pass.
3. Just because other people do it doesn't make it a good idea. Advocating policies that don't have any evidence to back them is one of the main reasons that our education system among other things is failing.
4. You said, "Meaning that people who support an unhealthy right like obesity should also take responsiblity and pay for the medical costs of the right they support through taxes. In addition to that, people who don't support the right to be obese shouldn't have to pay for the medical costs of obesity through their taxes."
If you don't support a right, then you are either telling people that they shouldn't or don't have the right to be obese. In either case, the government can't punish or reward people based on their support or lack of support for "obesity." Aside from the fact that "the right to obesity" isn't an actual right, support for that imaginary right isn't possible to measure.