How lucky are you usually?

Everything on a bicycle works together. You might be able to switch out parts as you mentioned, but I doubt it. The monocog cassette swap is a definite nogo. The crank swap probably won't work either because road bikes usually have a 68mm bottom bracket shell and mountain bikes are 72mm. We haven't mentioned whether the shifters and derailleurs will work, but they're going to be iffy too.

Frankly, if you're feeling lucky, I think you'll be better off buying a lottery ticket and planning on using your winnings to buy the bike that you want.