Is it possible to have multiple people editing the same project at once, similar to sharing a google document?
Yes. My partner and I use Dropbox and he shared his file with me. If I update the file he will get the updated file while he is working on it. Same vice versa. There is just one trick when you’re are all working on it. Scripting should be fine, but when you’re working on the levels no two people should be working on that level. If one saves it, it can mess up the progress of the other person.