There is nothing major to complain about that I can see. Flying twice in that small space is an unusual choice, but if you have found good prices, not a bad one.
I assume you have looked into http://www.flysas.com/en for regional flights. Their economy choices can be pretty appealing.
The flight from Oslo to Stockholm may only be an hour, but it will take 4+ hours from the time you board transportation to one airport and step into the center city of the other. The train trip is 6 1/2 hours and is within walking distance of each city center.
I see from your other post that you want to do the boat to Helsinki. Is this on day 13? If it is a RT excursion within the day 9-12 Stockholm schedule then I think that takes too much time away from Stockholm (at least two nights) and not enough time in Helsinki (only5-6 hours).
Have you considered flying home from Helsinki? That's what we did.
Have you considered doing the overnight ship from Copenhagen to Oslo, Nutshell to Bergen, and then fly to Stockholm? Basically it is trading an overnight ship for a day flight - more fun and efficient, I think, but I don't know how it compares cost-wise.