Kathleen,
Thank you so much for taking the time to share so much info! It sounds like the kind of astronomy course dd is looking for. And, it would be totally workable to do the field activities throughout the year. I appreciate your trying to analyze whether the Christian aspect would be a problem or not. It sounds like it probably would not, but I am going to have dd read through your post and help make the decision. The problem that she had with Apologia was that he was very condescending and used a lot of circular reasoning. It sounds like that doesn't exist in Signs & Seasons.
I first learned about homeschooling MANY years ago (early '80s) from Mothering magazine. Homeschooling was considered part of an alternative lifestyle that appealed to us. It's interesting the direction that homeschooling (and homeschooling resources) has taken since then.
Thank you, again!