Sorry you are having trouble! You can delete the entry from your SparkPeople account on the computer (not directly from the app). It looks, though, like you might not have attached the app to the SparkPeople account you are posting from. If you'd like to do that, you can do so by uninstalling the app and reinstalling. Then, the first time you open the app, be sure to log in as a current member with your SparkPeople username.
I haven't been able to replicate an issue with the nutrition information when adding a food. When you view the favorite in the app and click to view the nutrition information, do you see it there? I tried to take a look at it in your account, but as I mentioned, the app doesn't seem to be connected to your account at this time.