Quick Update: I was able to resolve all of my issues simply by removing all Mail accounts EXCEPT for my one iCloud account.
I had several accounts configured, but all of the others were Gmail accounts.
So I'm not really sure why something so simple would create so many issues, but I haven't had a crash since making the change.
Keep in mind, I'm using to having applications crash on me constantly since this issue began (at least once every couple of hours).
My fix was simple, turn off wireless or unplug your ethernet cable and do the following:
1. Open Mail -> Preferences -> Select "Accounts"
2. Remove all accounts EXCEPT for your iCloud account
3. Exit the Mail application
4. Enable wireless or plug in ethernet cable again
5. Enjoy