I agree that it would be cruel to regularly expose any dog to any situation that cause them to be stressed or anxious.
I'm sure that anyone with experience of a wide range of dogs would agree that not all entire males are a mass of uncontrollable hormones, though 
I (unsurprisingly, as I own an entire dog) do not agree that it is cruel to leave a dog entire, it depends on the dog and their reactions to varying circumstances. The medical benefits of castration are not yet established and there is some evidence which suggests that it may actually increase the risk of some diseases
agree unsurprisingly 100 percent. I find the assumption that by keeping my dog entire that it is cruel is a little insulting. Owners of entire dogs that I know go to lengths to ensure that our dogs are not in contact with in-season bitches to avoid any stress to the dog, and 99 percent of the time I can happily mix my dog with any other dog.
Also Rosie and Cob-web have said it depends on the individual dog - not every entire dog shows interest as Rosie has described above.
Most of the dogs on the shoots I go on are entire, and hand on heart I've never seen any problems as Dunbarney has described
even with stud dogs. Some bitches definitely do smell irresistable in or out of season, and in this case I would strongly consider spaying the bitch.
As for OP, it's an entirely personal decision based on your own research and requirements of your dog. Although I don't agree that only FT CH's should be breeding (popular sire syndrome comes to mind) I do agree that a dog should be a proven worker amongst other variables (ie health testing) before even considering breeding.
Not every dog that sires a litter becomes a sex pest, but a lot do - and I would seriously consider this scenario if you do consider using him as a stud. And neutering is definitely not a cure-all for any behavioural issues.
