What word is pronounced the same if you take away four of its five letters?

Hi. What nation has the most superheroes?

With strings I send a ball in flight, or keep the whole house up at night. In sport or chaos, loud and fast, my name fits both from first to last.

What can you break without touching it? What am I?

I lift the heavy, but have no hands, I travel aisles, but own no lands. With a metal grin, I play my part, what am I?