In a previous QA Managers role i was receiving so many of these that it drove me crazy. I was tempted to supply ridiculous answers just to see if any one was actually reading them. I.e Name of the pest Control Company - Mickey Mouse, as i was convinved that very few of them were actually read when returned. I didn't do it because i knew that the only people who would notice it would be the customer's auditors, and that would have put my customers in a very embarrasing situation and no doubt could have ruined the relationship between them and us.
I did do the suggested option of developing a precompleted Supplier Questionaire Answer Form, it worked a treat. I never had a customer come back and complain about it. I would double check that all that was asked for by the customer was covered by the completed SQAF, and modify it it didnt and return it. I would keep the modifications as part of the SQAF, as no doubt another customer would ask the same in the future. Obviously each customer got answers or information to questions they did not ask, but they never complained about this either.
Eventually the SQAF required no mods, so it took about 2 minutes to deal with Customer Questionaires. Saved me a lot of work, it was one of things I found myself asking - Why did i not do this sooner?
My 2 cents worth.