If the belt is visible (even half tuck) does it have to match your shoes? If your shirt covers the belt but there's a chance bending/reaching someone might see it peeking out will you look bad if it's not matching your shoes?
U dont have to, but i think the outfit looks much more coordindated when u do. Referrig to ur question, if the shirt is tucked in, matching belt and shoes is important because u men dont have much going on in the outfit to begin with so attention will be drawn to that. If the belt is covered, i wouldn't worry as much.
"Technically" yes. But in practice, sometimes it looks BETTER not to match; my only brown belt is very casual, when I wear a blue suit with brown leather shoes, I match it with a black belt - this looks fine in my opinion, someone would only notice if they were actually looking at this shit
For a suit (referring to below comment), it generally looks better to be matching because it's a clean cut look. Every day casual wear or even semi-formal doesn't necessarily have to match at all. It's known as color-blocking. As long as all the shades match well together, it works.