Well I’m not working for Epic but I tell you the information I got:
- At the moment unreal is free to use for architectural visualization and it has been for the last years.
- You have to mention UE in your product, see attached link.
- If you create a built and don’t give away the source files then your privacy is as guaranteed as it can be with anything you give away on the internet. I don’t know of any case someone did extract source content from a built game or visualization. - It seems to be a bit saver than iCloud.
Hope that helps.