if the outer joysticks have more than four buttons, it's either a mistake or a use other than MAME, like other emulators that tend to have more buttons.
On the outer joysticks angled question, people angle the joysticks because they angle the sides in to give people elbow room while still keeping a small sized panel. Typically, someone looking at the screen interprets it as a flat pane pointing at them, even though in perspective it's really kind of crooked. Then, most of the time they'll push up, ie away from their body, to move up. It works.