I think there is nothing wrong with focusing on 3d, but the reason I started with 2d tools is because I wanted to workout all the UI controls while doing something simple. later I am also planning to work on 3d stuff, so in some way you are actually ahead of me and of course I also still have lots of bugs to iron out so it's not all rainbows and unicorns, yet .

the parallax scrolling is very easy to achieve. all you need to do to create a background that seems infinitely far away is set the position of that entity to the position of the display (the scene to screen transformation manager). if you want to make a layer seem a bit closer then you just need to set its position to something like dipsplay.position * 0.9 and you will have a parallax effect.