If you login with your usual, normal account, ctrl-click does NOT work as expected. But it works with 5.0.36. Is that correct?
If so, I think that it's more than obvious that there's something interfering with VirtualBox in your account. What could it be? I have no clue.
Let's start with the easy ones...
- There seems to be no 3rd party kernel extensions installed, so that's out.
- The Firewall and Filevault are out. Not only are they Apple provided, but I don't see how they would interact with the mouse.
- I would think that Symantec's Endpoint would be enabled for every user, but it's really weird that it doesn't have a kernel extension installed that would enable that on the system level. Really, really weird... On the other hand, from a quick reading on their website, I saw that they have a feature called "Blocked Devices". How that works, I have no clue, but it seems that "devices" is pretty generic. At some point they warn "Do not block your keyboard" and "the USB wireless adapters". I don't like the sound of this.
- And finally the tablet; the obvious candidate. Check its preferences and see if you can dig anything.
Finally a general question: you have Firewall, FileVault and Symantec Endpoint installed. Are you logging as the computer owner, aka administrator?