Also your input should be ending at 14933 not 14952 (or 14938).
Holding B while Jumping does nothing. Your speed doesn't decrease or increase, it ignores the running value. 4-2 was very, very sloppy. Why the heck am I looking into this, oh God help me stop typing what's wrong with this when I already provided something that was much faster.
"I didn't use many glitches because it was really hard to use."
Is a big fat lie because the biggest glitch which was used was the flagpole glitch, use of the wall-jump and the other one was getting to 8-1 without the vine.
Also, FIREBALL! YOU GOT A FIREBALL AT THE END OF A LEVEL.