That was very impressive and entertaining to watch. Favorite parts were avoiding the coins jump on 8-1 and using the high pipe without using the coin block in the castle stage.

So true.  There was a lot of hesitation (at least I think that's what it was) before making those jumps while avoiding the coins on 8-1, losing the life while performing said jumps and actually celebrating after completing the jumps. 

So there's definetely much room for improvement.

The lost life was the only mistake...you get points for every second left on the clock when you reach a flagpole so you have to do the zero second trick in order for this to be a low score run so there is no point in rushing through things...

Yeah, but you get no points for taking warp zones or the axe, so there's always the possibility of completing those stages faster.  Not dying will cut the biggest amount of time, but 1-2, 4-2, and 8-4 could possibly have been done quicker so there's always the chance to lower the amount of time it took to complete by doing those levels faster.

The speedrun of SMB is frame-perfect. It literally cannot be improved. This can't be more impressive than that.

I would find it very hard to go through and not collect anything in a game

wow and why

let's bow to the king