Strange Questions That Pop Into My Mind at Odd Times and Without Obvious Reasons #784,589,045

In The Matrix, agents are irresistibly strong and incredibly fast. They can e.g. dodge bullets. And an agent can re-spawn occupying the body of anyone who lives in the Matrix.

So in the subway fight scene, why is it that after Agent Smith is run over by the train, he has to stop the train (much more quickly than trains actually stop, btw) and exit the door like a regular passenger?

Why not just break a window and jump out? That train isn't moving as fast as he can move, and dealing with the effects of jumping from a moving train onto a concrete platform doesn't seem out of line with his abilities.

Or, better yet, why not just occupy the body of someone walking past the station so he can intercept Neo at the top of the stair instead of chasing him from behind?

Just wondering.