I think the choice charcoal vs. navy is purely a matter of personal taste. Both are equally correct and both are extremely versatile.
I agree - even though I think a ticket pocket would be fine. What I would add is to keep the suit well proportioned, i.e. no skinny lapel, jacket and trousers not excessively tight or skinny. Also combine it with a shirt, which should not be skin tight neither when you are standing nor when you are sitting.
I agree - black is the classic / conservative shoe color for both navy and charcoal suits. Most SF members (including myself) consider the combination dark brown shoes and navy suits aesthetically a bit more pleasing, but in the most conservative business situations incl. job interviews I recommend playing it safe and sticking to black oxford shoes with no or limited broguing.
This is what I'm thinking of. Black is a classic combination, but I find dark brown to be a much nicer combination with navy. However, since the black suit (which should subsequently be used for evening only!) can only take black shoes he's better of focusing on a good black pair (balmoral style, either plain toe or cap toe with no detail work).