Answer to last riddle: An autobiography.
Horray! You guys got it! CD-Roomba said "Life's work" and dende said "his own painted biography", both of which were very close... Notforeverbody was officially the first person to give me the word I was looking for, autobiography. Haha it's funny how Timo guessed wrong which led to everyone else guessing wrong =). It's all good, here's another chance for you guys:
It is greater than God, but more evil than Satan; the poor man has it but the rich man doesn't; and if you eat it, you'll die.