Historically, the term governor was used both in England and the US to mean a person’s father, cited from 1827.
It is also cited from 1844 as a form of address, meaning sir or fellow. I think it died in the US while still in the 19th century. But continued in England.
I’m afraid to say that Don Cheadle’s awful Dick Van Dyke accent - and the dreadful lines he was given to perform - were the only things in that film that I disliked. It was as bad as Sean Connery in pretty much anything he’s not meant to be Scottish in. If the actor isn’t good at accents and you’re casting a London part, for goodness’ sake get a London actor to do it. Or make the part’s nationality fit the actor if you absolutely want him in that role.
As for his non-billing, I guess that’s Hollywood for you. There were so many bigger names that he got shunted.
He presumably asked to be uncredited. I don’t think that there’s any circumstances in which an actor can be forced to be uncredited. Usually when an actor is unbilled it’s because they’re a major actor in a small role and they don’t want to fight it out with the other actors about who gets the higher billing.
When in London last week our hotel-link driver asked a construction worker if he could take his “hole” - which I found out was his recently vacated parking space. The construction worker told him “There isn’t going to be a hole in a second, guv” and we took off looking for another.