14) You can do this already (draw outside the frame). If you hit A you will see everything including what is outside the frame – and you will be able to move it into frame iff needed.
15) Sure. On our todo.
16) We are using the what we get from the Wacom with adjusted pressure curve. But if for some reason it feels different anyway, you can set your pressure sensitivity in Wacom settings on an app for app basis.
17) You could try importing a png or jpg – your paper texture. It will come in as a “reference layer”. You can then adjust the opacity of it at the bottom of the layer column in the x-sheet. Of course that doesn’t alter the texture of the pencil, but at least it takes away the super white background like you wanted. Would that work for you?