Looking for some feedback on photos rejected for technical issues, Thanks

Hello,

Composition, white balance - in the first photo, I think it is a bit too pink/blue, 2nd photo, you have flies? in the sky, they should be removed, and composition is not very good, and the same situation with the last photo, also lens flare from the sun. The lens flare is not good here, it cuts right through the photo.

Have a read of this from Adobe about how to create better photos:
https://helpx.adobe.com/stock/how-to/tips-stock-image-acceptance.html?set=stock--fundamentals--adobe-stock-contributor

It may help.