I managed to shapeshift my body entirely, what is most spectacular is the way I can manipulate my arms into anything that I want. In my last dream, I realized I was being "played" by something in my dream in which I then became lucid, so I formed my hand into an shadowy mess and pierced through his head. I also have full control over appearance, I can literally take the shape of anything that comes into my mind. If I can do this in a dream, can I also bring this skill into the astral?
Yup.
Place the "Intent" to shift into whatever you want.