Also; so loosely-phrased, it looks like they are asking for indeminity for any problems prior to his ownership also John?
Emphasis on "so loosely-phrased". Obviously what matters is what ends up in black and white. It is generally an unobjectionable and perfectly reasonable proposition. Concerning "small businesses that are used to being sued", any successful business can expect to be sued. Legal disputes happen, and legal costs, insurance, etc. are just another item on the balance sheet along with garbage collection and utilities. Generally speaking, large publically-held companies have a tremendous responsibility to their shareholders to take all reasonable measures to limit potential liability. That's what insurance is for, and that's what indemnification clauses are for. Of course, any indemnification clause is only worth the indemnor's ability to back it up, which normally translates into "good luck enforcing that". If an indemnee is sued, they are still primarily liable for any judgment, and have to bring a separate action against their indemnor.
But, again, they don't know if you've used the domain name for spam, fraud, phishing, or any of a whole world of bad things, or what baggage they might have to carry as a consequence of that. If you are comfortable with whatever you've done with the domain - which you should be - then a statement to the effect that you would assume future liability arising from your own actions should not be an onerous obligation.