Chinookman,
To stop your Yahoo mail completely, go here:
https://bis.na.blackberry.com/html?brand=mycingular
This is the page where you set up emails to push to your BB. Log in, and where it says Email Accounts, click on the trash can/delete icon next to Yahoo, and problem solved: no more Yahoo pushed to your BB.
You can also do this from your BB, just not the way it appears that you're trying to. We can walk you through that (and someone did above, actually). Let us know.
ANY mail from BIS will show in TWO places (and NOT EVER in BB Messenger as mentioned): Messages (the catch-all Inbox for all messages delivered to the BB), and the INDIVIDUAL email account icon (Yahoo in your case). WHEN/IF you log in to your BIS page as per above, the YAHOO mail icon will disappear. You will still have the Messages icon, you just won't get any more email from Yahoo.
YOU DO NOT NEED TO WIPE YOUR DEVICE! And as mentioned, even if you do, IT WILL NOT STOP Yahoo mail from being pushed UNLESS you follow the steps above, and mentioned by SEVERAL others.
This will ALSO alleviate your Profiles issue with Yahoo (if I understood what you're trying to accomplish there correctly: stop the phone from notifying you of Yahoo mail arrivals).
Ya, I'm yelling. We're actually trying help you. Spend a minute to help us help you. Flame me if you want, I just won't answer. You're in the right place to solve all your problems, if you let us.
Steve