No one's imposing his religious values on anyone else simply because he doesn't violate his own religious beliefs by paying for a murder.
Except the business owner isn't paying for a murder, he is paying an insurance company. He is no more paying for a murder than if he hands over a salary to a member of staff who in turn uses the money to fund their own abortion.
Very few fingernails clippings are capable of living as complete human beings outside of the womb. But that's actually irrelevant to this discussion since the point is whether or not one person should be forced to violate his religious convictions by paying for someone else's. It's not as though the employees who think that a fetus is a fingernail clipping are being prohibited by their employer from having an abortion, you know.
This line of thinking is still seriously muddled. Paying an insurance company who may, at some point, fund a member of your staff having an abortion isn't the same as paying for an abortion. If people are so concerned about indirectly funding something they would need to know just what their staff were doing with the money they earned - if paying an insurance company who later funded an abortion counts as paying for an abortion, why is paying a member of staff who later funded their own abortion any different? How is paying a member of staff who then went and spent their salary on pornography and maybe a prostitute or two any more morally acceptable? At some point we have to accept that once money leaves our hands we are no longer responsible for it because if we do anything else we end up in an endless tangle of fussing over where that money is going and how it might be misused.
No one is doing that and it would be illegal if tried.
Except that if an employer insists they won't fund a policy that might in turn fund something they dislike, they are imposing their views on others. And as I mentioned before, if a Christian is allowed to refuse to fund an insurance policy because they disapprove of abortion, should a Jehovah's witness be allowed to refuse to fund another policy because they disapprove of blood transfusions? What happens if your boss is from some strange sect or cult who disapproves of all sorts of modern medicine - should he be allowed to refuse to fund policies because he considers modern medicine to be morally unacceptable?
No one is just left to die because they don't have insurance through an employer-paid health plan.
No, but if they don't have health insurance they may find the bill difficult to pay.
In none of these cases is the employee prevented from having whatever legal procedure is called for simply because his insurance comes from some other policy. If he wants coverage that one plan doesn't offer, he can seek another--just as is the case with any of us and, for that matter, with the federal health plans under ACA.
... which ultimately goes back to the idea of separating healthcare from employment, no? If your boss is willing to fund an insurance policy but not a policy that covers your needs, aren't you better off taking a salary increase instead of an insurance policy so you can buy your own plan? And wouldn't the market become far more transparent when costs were clearly visible, instead of being hidden away in corporate expenses such that most employees never see them?