Hi Becky, Sorry to hear that you are feeling so stressed with the house hunting process. It does sound like you had a pretty typical first day out there though.
I agree with someone else about making the list about what you are willing to work on in the house. I know that wallpaper is just cosmetic and an easy fix, but when we bought our house, it was COVERED in wallpaper (from the 60s, mind you). Years later, we still have 2 rooms that need to be de-wallpapered and painted. But we are also not as industrious/or have the funds required to finish fixing up our home as fast as we would like. Life always seems to get in the way. So as current homeowners, I think you guys will know best about what you can realistically manage to fix in the new house.
Also, I agree about hiring someone to professionally clean or steam clean the hosue to get the smells out if you end up with one of the ones you mentioned. In terms of the county appraisal, from our personal experience, our house apprasied a LOT lower. However, it wasn't an up-to-date appraisal of the house. The appraiser has to be allowed into the home, so if the owner doesn't let them in, they might not know about any new renovations to the house. An appraisal of $20,000 less actually does not seem that bad to me at all. It seems pretty close.
Sorry, for the long post. Just trying to offer any help I can. Good luck with the search! And when you get stressed, switch gears and think of how excited the girls will be in two months in Disney!