1. Nope.
2. The game data is stored in the Machinarium.sol file, and this file will need to be copied and transferred to the other computer if the giftee wants to continue playing where he or she left off. Assuming your giftee has Windows installed, information about where this .sol file is stored can be found here:
https://forum.amanita-design.net/index.php?topic=1097.03. Well, the only difference is that buying the game through machinarium.net will get you the full soundtrack—which is phenomenal—whereas buying it through Steam will not. However, if you purchase the Humble Indie Bundle #2 (
http://www.humblebundle.com/) sometime during the next couple of days, you'll get the game, the soundtrack,
and a key to activate the game on Steam, so that may be your best bet. ;o)