Get an ASHI inspector and have it inspected. Include a condition in the contract based upon the results of the inspection. That way you can back out of the deal if it needs too much work. Then submit a new offer that allows for the repairs needed.
That big hill is a major problem that needs looked at. It could be serious or maybe a few warped joists which would still be a lot of work.
Since your from Texas, post back if it happens to have a soaker hose laying around the perimeter of the house and if the house has gutters. Some of us would like to know.