Don't just look at the interior as a wonderful place to live, look for the clues that it can give about the rest of the house. Floors are not supposed to be unlevel, they should be solid and sturdy. Unlevel floors and doors that stick, bind or drag may indicate the structure has moved or settled. Are there cracks around the windows? Look for wear and tear and abuse. These may be indicative of how the owners maintained the property in general. If the appliances are damaged and old, the other systems may be also. Look at all stairs. Are they sturdy and easy to walk? Do they have good rails?
There are other concerns you may not be able to see. You may need to test for asbestos, radon gas, carbon monoxide, lead paint, formaldehyde, volatile organic compounds, pesticides, or electromagnetic radiation.