Not that I enjoy trying to find loopholes in the game (and especially not such obscure ones,) but I found a small glitch in your menu system:

Though the units present in each tile of the menu are repeatedly ordered to move back to the center of their repective tiles, I've found that this isn't quite enough...

After repeatedly issuing a move order to the Protoss Shuttle and the Zerg Overlord, I managed to displace the Overlord to another tile and broke the Shuttle from the menu portion of the map completely! Following this, a series of triggers (that were not really designed for such an occurence) began firing, and I eventually exited the game.

Though this would be a little time-consuming, I would suggest creating border locations that teleport the units back to the center of each tile should they enter them, instead of having locations that repeatedly order the units to the same spot. That way, you can prevent such occurrences with a (slightly more) failsafe system.

Note: The reason why this somewhat pointless loophole is even the slightest bit significant is that players who "liberate" their shuttle can use it to ferry their main character to normally blocked places, opening up an avenue of pseudo-cheating. (It really isn't effective cheating, as I know there are a number of triggers that require prerequisite conditions to be fulfilled, limiting access to the number of quests available. Anyways, who are they cheating against- themselves?)

Well, correct it if you want to, because as I said, it really is just a rather trivial and obscure glitch.