Of all airports in Ireland, Kerry is best placed to prosper from routes sustained through inbound tourism. And yet it has only a couple of seasonal routes to Frankfurt-Hahn and Berlin. I'd caution against relying on inbound tourism to sustain the airport.
More realistic is summer seasonal sun routes, maybe a Canaries flight in the Winter and the prospect of attracting an airline like Ryanair for a London route once the runway can handle their aircraft.