Cause of death, my guess, Brystsvaghed. Google translates as "Breast weakness", not sure what that might mean medically. There are quite a few with this cause of death on that page.
There were no fixed spelling in Norway at this time so it was up to the one who wrote how he spelled Musketeer.
I'm not able to read Ane Marie's residence. I think it ends with -veiten. Here about veiter in Trondheim; only in Norwegian: http://no.wikipedia.org/wiki/Veit
Interesting about the Musketeer aspect. My only knowledge of Musketeers is A. Dumas' novel....French swashbucklers carrying swords! I never associated it AT ALL with carrying muskets nor with other countries. Fun to find this out!!
Here is her husband's death, but it looks like he died poor or in the poor house in Trondheim. Haagen - #124