from SonicKaos' Pax Experience...

"- I don't know how many objects you can have in a created park, because I wasn't able to see that. However, I do know you'll be able to save/download up to 100 created parks at a time. You can also edit downloaded parks and edit them, but if they are uploaded again, it will always credit the original creator as well as the new uploader (so if you steal, it'll be known). "