Strictly in my own opinion, I would not never touch a system coded by this individual after reading about his activities on this forum.
Interaction with a monetary/credit system requires trust and regardless of the individual that may be the front man for this system, the underlying individual who is developing the system should not be trusted. Again this is strictly my opinion and only that.
I would say that your opinion is sound in it's reasoning.
However, he can still feel free to code it and we can inspect it for backdoors or flaws. If he does a great job people will donate(For the repayment) else they will just say how much he sucks.