One realistic issue I'd like to nitpick at.
I'm no expert on the workings of owning a business, but doesn't the government check where you get your money from? If Nick suddenly acquires all this wealth and uses it to pay off his mortgage, wouldn't there be some auditing of some sort to prove the money came through legitimate means? I suppose it would have to be laundered in some way but I was hoping to hear other opinions.
Of course this is by no means a showstopper, I quite enjoyed the movie.
In the words of Otto:
Zeppelin Rulllesss!!