It must be nice to have the time to draw
Already graduated from comm art school, and the industry has practically died. Back to school with my hack ass, this time for psychology. But regarding your sketches.
Looking through your stuff, it's pretty clear to me that you have a good knowledge of the basics, body structure anatomy etc. Yet your style lacks any "hook" - there's nothing here to differentiate yourself from everyone else.
As much as I like Manga/Comic styles, there's a huge glut of artists doing it right now. And while you are good at it, I don't think you're good enough at it to stand out from the crowd with it. I'm not saying give up, i'm saying experiment with how you do art.