I’d be surprised if the F50 couldn’t use Warburton from a strength point of view. I haven’t got the figures to hand, but I thought its MTOW is similar to the Dash-8, and I think the F50 was rated for gravel operations (bit I’m open to correction on these in case my memory is too christmas befuddled).
I’ve flown into Warburton many years ago, and there are no swamps or marshes that would potentially disqualify it from having sufficient strength. It struck me as a typical bush gravel strip, with the surrounding ground being hard as a rock (whilst dry). That means that the runway is built on hard ground and should be up to the job. About the only concern could be in the wet if the whole area gets soaked – which leaves 9990 days out of 10000 available for use.