@jmac they are very much compulsory as the application can not progress on their screen without the box ticked. they are not aimed at being Personal and if no is ticked it moves on to the next question if yes is ticked to the likes of Medication question im sure it would then just open another generic form resulting in the applicant confirming they have not been excluded from driving on medical/medicine grounds etc.
we were pre digital order last time (3 years ago) but did get asked the questions whilst sat at the salesman desk, but didnt think anything of them and to be fair would of said we never got asked had i not give it further thought and checked over some paperwork after reading your Post.