I would find it extremely useful if there were more icons on the minimap, indicating where things such Party Pads, golden gates, and even normal gates are. It currently shows the Elevator and Golden Keys, but nothing else (as far as I'm aware). These have been quite useful so far, so I think more icons would be even more useful.
Golden gates do appear with the golden keys once you've spotted them. I agree having an icon for party buttons would be useful.