Are there keyboard shortcuts to scroll to the top and bottom of a document?

If you hold fn and cmd at the same time, then hit ◄(left arrow) for scroll to top or ► (right arrow) for scroll to bottom, that should do it.

Sure. Just use cmd-Down or cmd-Up. The cmdkey is to either side of the spacebar.

On a Macbook, try fn+◄ (function + left arrow) for Home and fn+► (function + right arrow) for End.