You should also hire yourself a Real Estate Attorney. Sign NOTHING until he looks it over. Don't take the Seller or Seller's Realtor 'word' that what you're signing is, "... just a formality, and means 'nothing'."
Ask any bank if they have an Attorney look over the paperwork before they sign. And the bank does this type of 'work' for a living! The Seller's Realtor is working in the Seller's interest; not yours. Probably anywhere's from $400 - $800 you could hire a Real Estate Attorney. As with a Home Inspection, this $$$ is peanuts compared to the $$$ it might cost you if you HADN'T hired such professionals! Ask anyone that's had to hire an Attorney after-the-fact. THey'll tell you how much it costs. By hiring one now, you've already 'retained' legal counsel.
Oh, to answer your question, I don't think anyone from here can address your 'concern' about the barn. That's where the Attorney comes in. Oh, hiring an Attorney and Inspector is peanuts compared to the 100's or 1000's of $$$ you'll be spending over the next 15 to 30 years!
Did you hear that??! I just fell off my Soap Box! My best to ya and hope this helps.
Jay J -Moderator
PS: I'm not a Home Inspector or Attorney, nor do I do business w/either, nor do I receive any 'compensation' from them. I say what I've said from personal experience, along w/that of other's personal experiences ...