How can  I disable screen lock feature temporarily? I want to lend a tablet to a friend of mine and I'm sure he will try to prank me with a locked screen. 

What can I do to remove the screen lock, if he returns it with the locked screen feature enabled with a code or something?
One way to prevent this is to create an extra guest profile with help from SwitchMe:

Get root, install SwitchMe, create an guest profile, protect your profile with an password and enable SwitchMe's login manager feature. This allows you to recover the tablet by rebooting into your profile and resetting or deleting the guest profile.

Note that SwitchMe may not work with your ROM.