I am aware of that rule, but I don't like it, as it slows down the game (the goal is to bankrupt everyone, but anybody can get a huge cash boost just for being lucky).I usally play with the rule if you step on the Free Parking spot you get all the money on the middle of the field (so the money that was spent upto that point)
I wouldn't go for it being official. Getting at least one physical copy complete would be really cool, though...This looks pretty awesome. I never liked Monopoly, but basically anything with Wario in it makes it better, so I'm exited. If you need my help with anything just ask.
One question though: is this all conceptual or is this actually going to be programmed or created with actual boards? Probably not the last one, because you know... copyright and all that. But maybe programmed? Then you would have the hurdle of it basically having to be online.