General Techniques
MM5 - Charging the Buster
The Mega Buster will not charge while sliding in this game. As such, many times when a top runner is walking and charging, they did not miss a slide but instead are actively building a charge shot.
How Beat Tracks
Beat will attack an enemy if Mega Man is motionless. This is usually on the ground, but also happens at the peak of a jump if you are not moving left or right. You can use this to make Beat attach while jumping over Dark Man's shields, or to be faster to attack Wily Capsule.
All About The Super Arrow
The Super arrow takes two points of ammo to fire, though it can be fired with only 1 point of weapon energy remaining.
You cannot walk (or slide) off the front of a moving arrow - it will catch you.
Riding the Super Arrow drains 1 point of energy as Mega Man is on it. As such, many strats in this game walk off the front of the arrow, reducing the time Mega Man is technically still riding it, and conserving "just enough" ammo.
You can stand on an arrow stuck to a wall until it despawns without draining ammo.