Try harder. Orbitz turns up $1549 tickets on US Airways from IND to CDG for your dates. It only makes sense to buy miles when we're talking about a couple thousand; what you propose makes no financial sense at all.

I don't think either airline is in imminent danger of liquidation; if a sense of security is your top priority then spend a little more and fly a major European carrier, or find insurance. In coach, there is not a huge difference in experience flying a foreign carrier as opposed to UA, unless complimentary alcohol is very important to you.