I’ve finally decided to begrudgingly move over to UE4 from the UDK, and I’m wondering if it’s safe to house multiple projects in one installation?
With the UDK I always had a separate install for each project.
If you mean having multiple created projects and single engine installation, then yes. I currently have 9 concurrent projects and never had any issues 
Perfect, thanks!
Yes, I have 24 projects on one at the moment.