I don't think he was a "crook" in the traditional sense. I think he had a dream and, as happens to so many, he cut corners and did things he shouldn't have in an "ends justifies the means" way.
That certainly doesn't make it any less painful for people who lost out, but there is risk with any investment. If you can't afford to lose it, keep it in the bank.
Buying a huge quantity of cocaine that he planned to sell is hardly cutting corners.
Perhaps not, but there was larceny in DeLorean's heart and it began to show long before the drug deal. He conned the Northern Ireland Development Board into footing the bill for this very ill-conceived car. John DeLorean was just a high class grifter. As someone once said; "More money is stolen at the point of a pen, then the the barrel of a gun". Delorean used a pen until it ran out of ink and then turned to drugs for a refill. Now John has the chance to try and cheat the Devil himself.