Sounds like you need a confirmed booking to get the visa.
Confirmed booking means that you don't have the ticket issued (and don't need to pay at this point). Any TA can do that. Later when you have the visa you can either issue the ticket as booked or look for something cheaper (even on different airlines). There is no link between your visa and the specific booking, you just need to arrive at a location allowed for your visa (keep that in mind, your first arrival in Schengen needs to be covered).

As suggested before you could also look for a fare which allows cancellation in case of visa denial. If you book thru a TA he most likely will still charge his fee.

The potential problem with that approach is that fares which allow to book and hold a reservation are usually higher and the cheaper fares are not available later.

Not sure if award tickets allow cancellation if the visa is denied. But most programs allow cancellation and refund of the miles/money for a relatively small fee.