I think that yes the airport is viable in some form and it can turn a profit without a doubt. With passengers too!
But capex is required, and throwing money at the current terminal as is whats been happening is just delaying the inevitable. The walls look nice and clean with the new coat of paint but people still trip over the buckets catching the drips from the leaking roof whenever it rains (and yes it knows how to rain here!). The new duty free looks nice but in winter passengers will be shivering from the draughts as the money used for heating is literally blown out the windows.
The solution to retain pax ops is a basic new design low cost terminal. Several ex-PIK destinations have such buildings that could be used as an example of efficiency. RZE is probably handling the same amount of pax that PIK now is with the reduced schedule this year. Or even BZG, while handling less pax now, is capable of handling as many pax as PIK does. All nicely designed, modern, simple to run buildings.
The area surrounding the airport is capable of providing over 2 million passengers per year to the airport; this is historic fact. The population isn't getting smaller, the recession is over. The airport simply can't compete in its current form with the other 2 airports which have invested in their infrastructure.
A few other hypothetical questions;
Does the airport really need 24 hour radar approach control? Revert to procedural arrivals for the wee hours and keep just tower.
On the same topic, does it really need full RFSS 24 hours? Reduce it to CAT5 overnight (still suitable as an alternate for narrow body arrivals to GLA/EDI).
How much does it cost to keep the runway lights switched on overnight?
Runway 03/21; is it really worth the odd delayed or diverted flight on stormy winters days when the crosswind on 12/30 is out of limits to justify keeping it open? Only PA28s, etc use it normally.
Staff; is it me or are there always a lot of people milling around? I've seen first hand in other small airports where 1 person does checkin, then assists with boarding and then prepares the load sheet and dispatches the aircraft. Even in DUB, the dispatcher mans one of the boarding gate desks scanning boarding passes.