I've had good luck using Graphics Gale to manipulate palettes, in case you haven't tried this one. There is a free version at the above link. It's a contemporary program as well and let's you drag and drop single or multiple colors from one palette to another. I don't know it does all the things you are wishing for but it met my needs. If you have tried it already sorry for wasting your time but perhaps some others will find the above useful.