name='batman']If you are a jobbing actor you take what you can get. It is only 'names' who have any billing clout and it is usually worked out at the contract stage between producers and agents. It doesn't really have anything to do with how much you earn or your talent .... it's to do with your 'marquee value' as far as the producers are concerned, but for actors it is primarily a status or ego thing.
Re your 'and' query .... the answer is usually 'yes'.
Screenwriting credits can be amusing too. If you see a screenplay by 'Joe Bloggs and
Fred Bloggs &
Bill Bloggs', that usually means that Joe worked on it by himself but Fred & Bill worked together. The permutations of 'and' and '&' use can be very funny.