I am glad you are neutering him. You are a very responsible mom. I am sure he will be fine. It is better to have the wart removed when he is being neutered as it will be cheaper for you as you will not have to pay double for anesthesia, boarding etc.. and it will be better for him although anesthesia is generally very safe if used by a proffessional but it is best to put him under as less as possible and he wil already be under anesthesia.