I don't think any of us are qaulified to give medical advice here, but my experience with Chloroquine has been no problems at all. Caution: I once took doxycycline on a trip to Hawaii and boy did I sunburn! Read those cautions on the various drugs yourself...!
The Double Edged Sword: I used to spray well with Deet before leaving the room, morning, noon, evening, etc - but then learned that wearing Deet into the water kills coral, and it doesn't take much! So I quit using Deet until after diving for the day. You can still spray your clothes with Deet I suppose.
I don't know about your skeeters up in Norway, but here in Texas we have them at least six months a year. The worse exposures are early morning, evenings, especially dusk it seems - or anytime you walk thru vegetation.
Do read our CDC cautions on vacinations: Tetanus up to date, Hep-A, etc. - vaccinations generally suggested to all in Texas for normal lifestyles.
Well, of course I have to make up my own mind how we do with the malaria plls, but I really appreciate all the inputs anyway.
Our mosquitos in Sweden (neigbor to Norway) can be really bad, but we don't have them in the winter/early spring (from November to April). We have lots of repellant, most of them contains DEET.
Don't know anything about if this is destroying the corals or not. I hope not.
I have all the shots, like tentanus and the other basic vaccinations up to date and they are good to have pretty much wherever you travel or at home.