We’re talking about Christianity, not karma. The commandments don’t have a footnote on them that says “can be ignored when you are threatened.” The one about not murdering is pretty clear. And the one about having no gods before God is pretty clear as to who should be feared more than the government.
1) I agree with you that karma is not relevant to this discussion. A Christian store owner is in view, who answers to God for his deeds. There is no possibility that a Christian can voluntarily support the murder of innocent children. Karma and Christian morality are by no means equivalent. See discussion here: http://carm.org/karma-and-sin
2) On the other hand, I agree in part with TC in that coercion can mitigate guilt, even in a Biblical system of morality. In fact, Jesus addressed the tax question head on. He knew all things future, so he knew this would be a major threshold of moral challenge for believers down through the ages. Tax money given to Caesar was used for many things not compatible with Christian morality, up to and including the murder of innocent people. Yet Jesus teaches us to pay the tax. It’s Caesar’s shiny trinket. Give it back to him. And if you don’t have enough, go look for that fish with the coin in it’s mouth. God Himself will provide you with a way to pay the tax.
The decision by Roberts that the mandate is a tax will, I think, prove to be providential. Remember who Obama is. He is no mere dictator. He is Doctor Moreau, believing he can transform our society, that is, us, through systematic deconstruction of the judeo-christian paradigm, no matter how painful that might be to his subjects. This means it is important for him to use tools like the mandate to tear us away from our convictions concerning the most fundamental of our rights, for if we can be moved off that, we can be moved off anything else, and all things become negotiable. But it appears God has already anticipated this move, and provided us with a means of continuing to live and think and act as morally free Christians, in obedience to Christ. We pay the tax, and continuing preaching against the sins of our Herod, and rely on our God to bring him to justice.