I'm sorry Ellen but, I just don't see why you and others I have seen posted about similar situations get so worked up over letting the end user do the processing.
Look at it this way, back in the film days you might be hired to do a shoot and FedEx the undeveloped rolls of film to the client. You had no idea of what you had until you saw the final product.
I see and understand your wanting control but, they are paying for it and if that is what they want then that is what they get. Even if they are just wanting to save a buck or two on PP work. If they screw it up then thats too bad for them they still owe you for the shoot. If you process it and they can't use it because of your processing then guess who won't be getting paid? Yep, you.
Manytimes a magazine, especially, will want the original file untouched. Sure you may know what your doing in PS but, are you calibrated to their ICC Profile? If not you may correct to what looks soooooo good to you and then when they get it there is nothing they can do because you have over blown a color temp in their profile and they can't back it off without residual effects on other colors.
My advice would be to shoot it and be in focus with a correct white balance and let them worry about the rest of it, just collect your check.
On shooting sports...If you see it happen then you didn't get it.