Disabling bonus stars is a good point. For the difficulty, not sure if that would work well: The problem is some of the players are inevitably casuals, so increasing the difficulty just means the very narrow part of the game that isn't as random - the mini-games - becomes not fun for them. And the Monopoly-style turn-based board play takes sooooo long, you can't really strategize where to go.

I really do think a Mario Party game with only mini-games so everyone plays all the time would be incredible. But again, maybe I'm just describing Warioware...