Wilbur:
I have a 30-year old built kit of the Kearsarge that has survived three moves (one of them across the country) with only minor problems so the pins on the mast to hold the spars are stronger than they might seem at first. I would suggest making sure that your rigging is functional as well as decorative. Standing rigging, lifts and other running rigging will stabilize the spars and take much of the stress off of the pin connections to the mast. With a little care, you can probably get by without gluing the yards to the mast.
The spars in my kit had a sag in them out of the box that I corrected by heating them in water and gently bending them to straighten them out. You can also reinforce weak spars by running a length of thin metal rod below the spar and securing it with thread wrapped around the spar and metal rod. I had to do that with the spar for the foresail (which was badly bent - probably when the sprues were pulled from the mold) and no one has ever noticed.
Hope this helps.
Mike