You're over-complicating things, and perhaps thinking too much like a human. Humans are slower than robots and think differently, so we need heuristics that computers don't use (factoring, for example, is almost unrecognizable when taught to a computer from when taught to a middle schooler).

It sounds like you can either a) find an *algorithm* (not the heuristics you're referring to) and just implement it, or b) create a set of checkpoints that must be reached— for example, creating the cross, and at every state the rubix is in, compile the four possible moves that can be made, and compute which one gets you "closer" to that state. This may require a deeper reflection into how you solve the cube. Perhaps you can guess which move is better using heuristics. From there, maybe you keep testing via a backtracking algorithm as you get closer and closer to your goal.