Your Realtor is not your home inspector, period!
So if your Realtor tells you that the roof looks fine and the foundation is strong, it may be a good opinion based on a general intelligent observation, but it is not a substitute for a home inspection.
A home inspector is another opinion, by a "hired gun" that a home buyer or seller pays, regardless of the outcome. The home inspector is contracted to perform the inspection duty, whether or not they find anything wrong, and, there's almost always something less than perfect.
I don't appreciate home inspectors that freak out about normal things that they find in need of repair. On the flip side, I do appreciate home inspectors that do a thorough job and educate and recommend repairs if needed.
I've had a few inspectors recommend that people walk away from a house, I don't like this either. Why? You cannot assume to know the motivations of either the buyer or the seller to negotiate and remedy a problem, even really big problems. There is almost always a buyer for a property, at the right price.
While many Realtors are very observant and very educated in property inspection details and how to resolve and negotiate resolutions, Realtors must rely on other professionals for this service. In Montana our Purchase Contracts are very specific about this: