Insulate behind radiators.
You are right to ask these questions, as the present set up is putting your home at risk.
The big problem in Alaska, as with all places where it is cold during the winter, is that of interstitial condensation.
What happens, is that the humidity in the home, always makes its way to the nearest cold surface, where it turns into condensation.
When a home is built correctly, all the walls, ceilings and floors are sealed with, almost water vapour proof plastic sheets.
Turning each room into an airtight plastic box.
This ensures that the water vapour does not get into the walls, etc, condense on the wood (or anything else) and start mould and wood rot.
You need to correct this error.
The thing with baseboard heating is, that it radiates heat through 360 degrees, and convects through perhaps 90 degrees.
This means that most of your heat is going into the walls and floor, and not into the room to keep you warm, not doing your heating bill a lot of good.
The best solution is to add as much polystyrene sheet, or foam into the walls as you can manage. Making sure it is a tight, push fit.
If you can, get under the floor, and fill the spaces between the joists with polystyrene, this will make a big difference.
In the European Market area, the recommended thickness is 14 inches of polystyrene to meet the "Passive House Standard."
I know that is a lot, and you probably cannot fit that much in your walls, however, everything we do is a compromise, and six inches will save a lot of heat.This standard applied throughout the home will bring you heating bills down by about 80 to 90%.