While many could be said to be long shots, some in @simoncorbett posting are clearly far less marginal, among them Stuttgart, Milan, Hamburg, Hanover, Berlin, from a business perspective and perhaps a couple of the "ex-pat / holiday home" French destinations on a seasonal basis. I'm sure the same applies equally from MAN and SOU.
Then on the domestic front, EasyJet offering 2 x daily service from EDI / GLA is hardly business friendly, and there must be an opportunity for multi-daily frequencies on these routes. BHD is a route that has already gone to EIR.
I don't doubt there is room for a very much slimmed down, more cautious "FlyBe2", but almost certainly branded completely differently. Prudence will be the key word if they are to succeed.