The heck with your realtor's advise, get the inspection. At this point it may, or may not be something that allows you to negotiate price, or even who will correct any problems. I may help you decide whether you want to actually close. Material undisclosed faults in a house are a legitimate cause to allow you to back out of a purchase contract or renegotiate its terms. You have a right to know the structural and operating condition of the house, and I would cancel any contract where reasonable access is not provided to make that determination.
I am in California, and in a hot market. There is no such thing as a market so hot that the buyer should not carefully inspect what they are paying hundreds of thousands of dollars to buy. So you lose a house, bit deal. How many listings are there in your price range? I would bet there are a lot. It does not sound like your realtor is looking out for your interests. If they are also the sellers realtor, their primary fiduciary responsibility is to the seller. In any event, they get their money from a sale, not when you change your mind. You will have to be your own advocate.
As for the cracks, they may not be a problem, but no one can say without inspection.