I think it's important to remember that the medical form is not asking a doctor to certify that you are fit to dive. No doctor in his/her right mind would sign that. The form is asking for an opinion from the Doctor as to whether or not they are aware of any conditions that they would consider incompatible or contraindicated for recreational diving... I just think there's a difference.
To me the most onerous part of the form is about taking ANY prescription medications. For example, at one time I used to take Zyrtec for seasonal allergies and at that time it was prescription only. I still use the OTC generic that's still the exact same stuff......but don't need to mention it because it's no longer a prescription.
And lastly.......maybe I just am not seeing it....... but I don't see anywhere on the form where it states how long this form is valid for once signed by a doc?