You say, "In the 1851 census he is a Police Officer and that would seem to be consistent with his moving around."
I strongly disagree, there was and is no National Police Force in the UK, with individual police forces (formerly known as Constabularies) being broadly county based.
Moving around like you have described is more akin to the movements of a soldier and with mention of the Isle of Wight I would suggest possibly the Royal Garrison Artillery and then became a policeman after being discharged.
Genealogy isn't about guess work, you can use BMD and census records to build an outline, but you MUST obtain copies of birth records to confirm the father's occupation.
Finally you quote an email address yet state you are using a shared account. You don't need a subscription to post a message and receive replies on Ancestry's message boards.
Don't log in with the "shared account" (take care you don't get the account suspended by openly admitting that you used it) just go to Ancestry's web site and register as a user, if you can't do that try to reply to a message and you will be taken to a registration screen; it's free.
I've been replying to people for years without subscribing but by just being a registered user.