1: You can set on ACP to teceive a comission from every donation. It's in the screenshots.
2 & 3: This app works with Commerce and Commerce is pretty bad in that direction. The credit goes, as always, to the Account Credit and the project owner must request withdraw to actually receive the money from donations. So the admin must require withdraw approval, so if the project doesn't get all the money, he can proceed with refunds. That's the only way Commerce works, unfortunately.
4: Clubs do not work that way because it doesn't has permissions. Once you create a feature, FOR ANY APP, anyone will be able to create an item (topic, file, image, blog entry, advert, project, video, etc.).