"So, why not simply take control of the air tax in Belfast, and tax-raising powers related to it, and charge a tax of £45 - £50 for all bookings taken in NI for passengers departing from RoI airports, and use the funds raised from this to wipe out the equivalent financial loss to the NI Executive which would be incurred "
How? Are you going to get Expedia to do that for you?
Perhaps if the crayon munchers on the Hill stopped shelling out for crap like policing for Flegs and Camp Twaddel their might be more cash available in the coffers.
That ,however,would require a grownup approach to politics......no surrender...
(Other lunatic politically inspired money pits ARE available...the above example is just that...an example)