problems with Safari

Safari was my default browser. In preferences I have Google set to be the search engine and the home page - it is supposed to open every new tab. But lately it opens with "search anysearchmanager.com" apparently run by Yahoo. Also if I leave several tabs open it will close the site I had open and replace it with "search any..." page: very annoying. And now it won't load Facebook properly, says it needs Javascript which I assume it used to have. I would like to uninstall and reinstall to see if it would return to working properly but I can't uninstall.

Any ideas?