I've also posted a question on this board asking if anyone had any recommendations about what to do in mid-March since we will be visiting. There haven't been any responses, but I googled Halibut Point, since you had inquired about it, and now I know that will be a good place for us to go hiking. I also found out during my googling session that there is a festival the weekend of March 14-16, so maybe that is somewhere you and your husband can go and get more information about Sitka and Halibut Point. The website is http://sitkaspringfestival.com/Home_Page.php
I hope this helps. I think that is really great that you are doing this--I'm sure it will be a great adventure!