Your post was very informative and much appreciated.
The one insulating contractor said that the attic was not insulating enough anywhere in my house. I have about 6 " of the stuff that you roll out and it is all smashed down. He proposes blowing insuation in the attic and adding insulation to the side walls, near the ceiling in the basement. For this he is asking a little over 400.00. I guess that's reasonable. His recommendation for the crawlspace was to add a heat duct. I have called my HVAC contractor and he said he will come out to look at it. However, he doesn't think the heat duct is a good solution. I also felt around the french door in that room and can feel the cold air rushing in from the bottom. Also, the light switch that is there (how to resolve that one?)... I can feel cold air coming through it (is that the weather stripping stuff you wrote about?). The contractor did say that I had insulation in the wall... he checked near the light switch.
Do you think the added insulation to the attic above this room will help?
I will look into some type of new fireplace... I couldn't tell from your post, did you think that gas was better than wood for heat?