1. So far this build is SFW, but things will change in the future.
2. It's mostly linear in that it follows one main plot thread. You will be asked to choose either of your companions as your interest, at which point the story diverges for one chapter and comes back together. Afterwards there will be slight variations to the story based on your route and a few other decisions you make later on. There are a few different ways the ending can play out.
3. I'll work on an Android release soon.