Every time I go home I like to tackle a project with my mom. She really is great to work with because she sees the big picture and is pretty good about not letting things get in her way. Plus I love leaving a space a little more organized then when I found it.
Our kitchen does have cabinets but this open storage is what gets the most use.
My father is a lover of Ebay and each time I come home it seems our granite pottery collection has grown.
I am a strong believer of not getting rid of someone else's stuff if they don't give you the OK. It violates trust and isn't a long term solution.
BUT on the other hand I know how all the clutter can drive a person crazy. With my mother, we selected the plates, bowls, and mugs that are used most often. As we cleaned out other cabinets in the kitchen, we found homes for the extra on the top shelves that are rarely accessed. This way, if one of the everyday plates breaks they can quickly grab a replacement but aren't always out cluttering up the counters.