Is it safe to install Linux on USB?

Yes! You can use your own, customized Linux OS on any machine with just a USB drive. This tutorial is all about installing Latest Linux OS on your pen-drive ( fully reconfigurable personalized OS, NOT just a Live USB ), customize it, and use it on any PC you have access to.

How do I install Linux from a flash drive?

Insert your USB stick (or DVD) into the computer. Restart the computer. Before your computer boots your current operating system (Windows, Mac, Linux) you should see your BIOS loading screen. Check the screen or your computer’s documentation to know which key to press and instruct your computer to boot on USB (or DVD).