Thanks for your feedback, glad you liked the song :)

1. I assume you are talking about the melody in the second part of the song. That sound is indeed fairly high pitched and loud but I personally like that it kind of rises over the rest of the mix and plays its own thing for a bit. It just felt right to have the melody kind of independent from the rest of the track. But hey, that's my personal preference and you are completely allowed to have your own.
2. In the almost 10 years I've been making music I have never used vocals. I am way more comfortable expressing myself through sound design and instruments and I don't like my singing voice so I can confidentially say that the song would have probably been worse had I put vocals in. But hey, the stems are available in the song description, if you want to add some to prove me wrong you'd be more than welcome to do that :D