Well first off, who said we couldn't have references in Pokemon? Sharks with lazers is a well known internet meme at this point, not just an homage to Austin Powers. In addition, I had no idea what you were talking about for a second there with the Fakemon. Good call, though :)
As for Water / Dark and Water / Ghost, that's just playing on the typical aspect of sharks as terrible or ferocious (and Sharpedo already has that typing anyway!), while Steel type sharks? That's OUTRAGEOUS! Fire-type sharks even... with their bodies made of partially hardened magma, swimming in volcanoes :s
And finally, that statpool you gave is basically Sharpedo beefed up far beyond its limits, with Speed that allows it to sweep with either element of attack and moderate defenses and HP that allow it to take more hits than it should, given the extremely powerful offensive capabilities. fml
Cheers! Have a smile :D