Hi, Bill--
I'm not sure why you've decided on Motion OR Final Cut to create 2D animation. I've been doing animation for a couple of years (I'm an illustrator) and, while I'm now using Motion for some compositing for my current animation project, I mostly use either Toon Boom Studio or Macromedia Flash. If you want to do 2D animation, I'd highly recommend getting one of these programs. You can either draw your images in a traditional manner, scan 'em and bring them into the programs or draw directly into the program with a Wacom stylus/tablet. They are designed specifically for vector 2D animation.
Hope this helps. If you have any other questions, I'll answer them if I can.
Best Wishes,
-Elwood
Here are some links to check out the 2D software:
Toon Boom Studio:
http://www.toonboom.com/
Though they are dated, you might want to check out Steve Ryan's helpful and clear Toon Boom tutorials to get an idea of how it works:
http://www.steveryan.net/Toonboom.htm
Here's an animation I created (on the Toon Boom site) to test the Mac Version 3. I did it quite quickly, so don't expect complexity. I did it directly into Toon Boom using the Wacom Tablet & Stylus. I did the music using GarageBand.
http://www.toonboom.com/showcase/index.php?type=swf&id=elwood&Cartoon_Animations =&
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Link to the Macromedia Flash site:
http://www.macromedia.com/
Some artists who use Flash:
http://www.joemurraystudio.com/
(Joe Murray is one of my favorites and may use Flash and mixed media, I'm not sure how he does his animations. Great stuff, though.)
http://www.sandrocorsaro.com/reel.html
http://www.mudbubble.com/mad2005/main/mad_2005.htm