Exactly, for this price.. u get to boot in either one OS.
Yes, u can definately plug and play the USB thumbdrive into the
MacBook, drag and drop files onto the desktop without any hiccups.
When u are done... jus drag the USB drive icon on the desktop to
the trash bin... wait for the led light (on the thumbdrive) to goes
off and then u can plug it off.
Say, if ur macBook arrives new... u can straight away use it out of
the box.