Hello! Yes, rotating images is possible by going to the Image menu and selecting "Rotate Image". There are a lot of rotation algorithms, but we recommend either "Rotxel with Smear" or "Nearest Neighbour (Shader)" because these are the fastest.
Limiting the colors on export is not currently possible.
You can use a selection tool to create a selection, and then you can click on it to move it. If you hold `Control`, the movement will be snapped to the grid. You can read this for more information: https://www.oramainteractive.com/Pixelorama-Docs/user_manual/transforming#move