YouTube ToS and Creative Commons - will our app be banned?

Question

YouTube

We are writing an online video editor that will help musicians create a video for their music.
I uploaded my mp3, searched for a couple of videos on YT / Vimeo / Instagram with a CC license, cut / arranged, rendered on the server and uploaded again to YouTube.
Read YouTube API ToS II. Prohibitions, points 8 to 11 and became sad. For example, they prohibit "separate, isolate, or modify the audio or video components". What about Creative Commons?
The closest similar use case is in Coub. They also pull up to 10 seconds of any video from YT, leaving only the video, substituting another audio. I wonder how they managed to "agree"? Clarify, please, who is in the topic or in Google:) Will our service be banned, will they send a terrible letter
like Zamzar's ?

Answer 1

Creative Commons is different, what exactly is it there?