Belfast?? Ireland has Ryanair & Aer Lingus that do quite nicely thank you. Scotland really has only ever had Loganair. Lets face it, Air Scotland is not a Scottish airline. Yes there are smaller operators but Flyglobespan is the 1st major Scottish airline that I'm aware of (correct me if I'm wrong, please?)
I'm not saying that just as there is a specific route from GLA that there should be one from EDI, I just think that there is sufficient demand for this route (proved by load factors at GLA) that it would make some sense.
There is only 1 flight to Cyprus (LCA) from EDI with Eurocypria (seasonal).