Is it possible to remove the ":-)" smiley key in Swype for stock Messaging? I love Swype but have a minor gripe with it. 

Many times a word will be completely messed up so I hit the backspace key but instead accidentally hit the :-) key. 

In almost all programs there will be a return key instead. It appears to only be in the stock messaging application (though it's where I spend most of my time!). 

This is extremely annoying, as I never use the built in smileys (I prefer them without the nose, e.g. :)). Is it possible to remove that key and make the backspace key bigger or something similar? 

My phone is a rooted Motorola Defy with a stock ROM.
That's unfortunately not possible, Swype would need to provide a setting for this, which they don't. You might have more luck with third-party-messaging apps, but I doubt it, as this is a contextual feature that pops up whenever it makes sense for smileys to be inserted.