Yes, it is possible.
Yes, it is possible.
Sure! You can place the Windows 10 preview on your USB drive and set it as your boot device. Then you can use it as your primary operating system until Windows 10 is officially released. Just ensure the USB is formatted correctly and inserted properly.
There exists Windows To Go, though its availability in Win10 isn't confirmed. Consider this alternative: http://www.howtogeek.com/196817/how-to-c...e-edition/
Sure, it should last about 90 days. Would you like to repeat it using a different USB drive or method?
Instead of repeating the cycle every 90 days, you can generate a snapshot of the USB after completion and simply load it.