A bidding system for rostering is far better than someone else deciding where you fly to. You would have choice, currently there is little choice other than on the few request trips per year which are not always guaranteed.
An hourly flying payment is also far better than the current allowance system. It appears everyone looks at the trips that pay the highest allowances and then compare that with hourly flying pay.
Try comparing an hourly rate to the allowances on the trips that currently pay the lowest meal allowances and see what can be gained.
An hourly rate flying pay system would actually pay more than allowances do on most trips.