With respect to instituting universal health care, I can tell you that coverage for home births will NOT be one of the first battles fought. Rather, it'll be farther on down the line, when folks are tweaking the system and looking at what are the most medically and financially cost-effective methods of management and treatment. Please do NOT base support or disapproval of a universal health care system, at least in its initial phases, on whether it covers a few very particular sorts of things (such as home birth). There are harder battles to be fought, first.
Also, re subsidizing the less healthy (including those with less healthy lifestyles), you already do this, if you have health insurance coverage (and, in fact, if you pay taxes - Medicaid, the VA system, SCHIP and Medicare, among other programs, are paid for largely by our tax dollars). It will be little different if you provide this subsidy via taxes or via premiums (or cost sharing, or what have you). The only difference is that, in a universay HC system, you'll likely see more explicit forms of rationing taking place. Presently, rationing of course occurs, but is largely hidden, as it's done privately by private entities (largely insurers). In a public system, the rationing will largely occur at a public level. For example, in Oregon's much-cited Medicaid program, the state made a public determination of the procedures and diagnoses that it would cover, expressly leaving many out. It takes guts to do this; you can imagine the firestorm this created (and it wasn't without failures, as well). But in the end, it's the most responsible way to accomplish the task. And one might very well find certain forms of rationing occuring that would target those with certain preventable conditions. Then again, the heat from such a decision may ultimately prove too great to sustain. At least, though, those decisions would be out in the open, and would be potentially influenceable by activism.