MJB - I agree with most of your suggestions but eactly what training would you give to the pilot in rescuing the pax?
If you have successfully extracted yourself from a submerged helicopter, the LAST thing you want to be doing is going back in. The AAC lost a pilot doing just that many years ago - he became snagged and when the aircraft sank, he went with it.
Looking after yourself is difficult enough with the restricted movement afforded by an immersion suit and life jacket (even if it isn't inflated) such that trying to assist anyone else is nigh on impossible, even if the pilot is young, fit and uninjured.