My operating system is a MacBook Air laptop. I know, this is probably not the best choice for rendering performance, but it works pretty decent for gameplay.
I downloaded X-plane from Steam, and I can either launch X-Plane from Steam or with the desktop icon. When I launch X-Plane from the desktop icon, the main page loads (with the options of new flight, load saved flight, etc. With the 737 cockpit in the background) and then I can play it. I will also tell you that my laptop does not have enough storage by its self, so I had to buy a separate hard drive that has enough storage to support X-Plane. So when ever I go to play X-Plane, I plug in the hard drive (X-Plane will not launch with out it plugged in).
Yes, I am the sole user of the laptop.
I have followed the instructions from the link that you sent me:
Hope this helps,