While your eagerness is admirable, what you've presented is not a solution at all, but is simply a way to further aggravate the problem. Said problem is not that the Spore ModAPI Launcher never works with Steam Spore, but that it cannot be relied upon to consistently work with Steam Spore - injection failure can potentially lead to game instability or save data corruption if saves which depend on ModAPI mods are present during a game launch where injection has failed. As such, I have placed your instructions into a spoiler, with a warning discouraging readers from following them.
If you would allow it, I would prefer to remove the instructions entirely, but I won't do that without your stated permission.
That said...your hypothesis as to the exact nature of the problem, while similar to my own, differs slightly. This interests me. I will be investigating this further at some point in the future.
Congratulations, you answered your own question. Go buy Spore (and don't buy it through Steam). In fact, I'd recommend buying it from GOG. If you're tight on cash, wait until the holiday-season sale.