Re: How Do I know If This Is Safe?
One way to find out is to see if other folks have used it and if they then encountered any problems. You should do searched for Bumblebee in other forum sections to see what threads are there.
Other than that, there's not much else you can do. IF you were to contact the developer of the code, OF COURSE they will tell you it is safe. Anyone trying to distribute malicious code (which, this is NOT), is unlikely to admit to it.
If you're really concerned about damage, the best thing to do is to use something like Clonezilla to image off your current install to an external drive, so if something goes terribly wrong, you have a quick and easy way to restore the install to the prior state.
Ubuntu 17.04 Mate, Mint 18.1 Mate; MS Win 8.1, MS Win10 Pro.
Will not respond to PM requests for support -- use the forums.