Over the last few days I've been getting quite a lot of bug reports and feedback from a user. Please do leave you email address in the feedback form. It makes it easier to get back to you. Am not sure if you use twitter or follow this blog. I will try and answer one of your questions here.
Why should I add fefoo as the default engine even when it only searches on Google?
When you add fefoo as the default engine it uses Google without the toolbar on top because personally 95% of the times I want to search on Google. Thought the toolbar is helpful in most cases I would not like to be stuck with it on every page. To turn on the toolbar while you search from the search bar add a ":" (colon) in front of your search. Now if you are searching for ": Baby Shark Song" just add a colon in front of the search. This will force fefoo to show you the toolbar.