and at a long shot possibly doncaster or humberside
BHD2BFS I would say a very long shot, Ryanair had tried these routes from Dublin and they were a complete flop especially Humberside. I draw a comparison with Dublin as it had a much bigger movement of passenger than BFS to England. So if they wont work for FR from DUB they wont work from BFS/BHD for them either.
Flybe did Humberside from City airport and it didnt last long at all. Same story there.
There is so much extreme views on FR good to bad, and I find them fine to fly with (though not my 1st choice) but I am firmly of the view that in a market with limited demand (NI very dependent on home market as tourism market not huge, relatively speaking) inviting FR into the Belfast would ultimately P*** off the existing carriers and probably lead to erosion of there share of traffic and potentially put FR into a strong bargaining position, not what BFS need.
EI-BUD