Hi Atimholt, welcome to the group.
Just an idea, but before you go too far down the route of your cubic globe, a standard mapping trick used in the gaming world is to map to an icosahedron (no special bias, honest).
The projection here is similar to an interrupted sinusoidal, and will have less distortion than a cube. Because it is a 'standard', there is software available (some of it possibly free) that will take your map and convert it directly to icosahedral format, saving you a lot of calculator time.
I'm sure there are many people here who can help and advise you on all aspects of mapping, right from initial planning. You don't need to go it alone.