Help with a song: Undertale Heartache

[Enrico]

Hi all!

I managed to clean the song of what i think, were supposed to be noises (6000 notes in total!) with the help of another midi editor.

Now it's much more audible!


But i still have some questions:

-sometimes the  notes are not perfectly centered, or not have a normal period, what should i do in this case?
 Center the notes? Make them regular of duration?

Also:

-the very high pitch notes sometimes disturbs the other. Should i delete them? Or lower their volume?