Uh... huh. ... Buckaroo is the sort of omnicompetent hero you wouldn't want anywhere near your PCs, that's for sure!
In Conan-branded games, is having Conan in the game a problem? Only if they fight him. In Stormbringer, is Elric an issue for the PCs to be around? Well, yes and no; Elric isn't the problem, it's that damned sword of his. How about Kirk or Picard in Star Trek? Sherlock Holmes!? No, thank you; all are too competent (but can still be fooled)!
Titular IP characters are not who PCs play as--nor even often face in such games... How often is Cthulhu in a CoC scenario?
It's not like Buckaroo is immortal, especially burly, nor highly resistant to pain or capture.
But not to worry--we won't let him near your game table!!
I'm having trouble imagining adventures other than dealing with aliens from Planet X.
Hm. Perhaps you should get your imagination to exercise more?
At least we know the imaginary holders of the Banzai IP shouldn't bother selling their non-existent game to you. At our table, we're ready to join the Blue Blaze Irregulars (who, presumably, would be the organs and skeleton of playing characters in the game)... They're like less competent, even less well-equipped--but far more sane and appropriately light-hearted--than Delta Green Agents.