ncleflights is right that the bergamo route was ruined by appaling times - arriving into bergamo at 2355 (if you were lucky) and becoming tues / thurs / sat made it poor for a weekend away. when the route started it was once a week, so it obviously was doing well on that basis to encourage ryanair to make it daily, before then downgrading it.
as for torp, that route was a disaster from start to finish because there simply wasnt the market for it. Torp itself is a good 2 hours away from Oslo city and even if there was the demand for a service to Oslo there certainly wasnt to Torp.
Girona shows that if ryanair choose their routes carefully they could make a success of a one or two plane base serving dublin, girona, a couple of polish routes, alicante, palma, madrid, frankfurt, bournmouth etc etc
