Sorry to hear...
Extended warranties are tricky. You
MUST read all of the fine print and gather as much info about the warranty company and their policies as possible before committing to them. They will most always try to find a way out. Great advice on keeping ALL receipts and documentation of work performed on your car.
A far as the crankshaft breaking...I can't say this is a common occurance. Do a search here and on other sites and you won't find any.
"5. I'll reiterate what a lot of people are saying on this forum to prospective new owners: don't buy this car unless you've got EXTRA money to spare. "
I don't think they meant an extra $16,000 to spare! What happened to you I don't believe is normal. I think people were referring to Porsche Marked Up intangibles such as top problems, cracking coolant reservoirs, RMS, oil filler tube replacement, etc...
Good luck and enjoy the car when its nursed back to health!