When you wipe your iPad, the first thing you have to do is disable Find my iPad, and then sign out of iCloud. This means your device isn't connected to the other Apple devices any more, and should not have an influence on their content.
It's not that difficult to understand iCloud PhotoStream, or iCloud Photo Library (I hope):
PhotoStream makes your images available on other devices with the same ID, for a limited time, and there's also a limit to the amount of images that can be synced by it. When you remove an image from your PhotoStream, it will also disappear from PhotoStream on all other devices synced by iCloud. The image will not disappear from the one device where it was saved. It will still be there in the Photos album or Camera Roll (except if you remove it from there.)
iCloud Library syncs images and videos between devices, without limitation of time or amount. When you remove a picture from one of the devices connected by your iCloud ID, it will also disappear on every other device using that ID.
Both, iCloud PhotoStream and iCloud Photo Library, are not meant to store pictures/videos.
Hope that helps.