You don't have to edit the plugin.
If you really want to remove the meta tags, you can use something like this in your theme:
remove_action('wp_head','sfc_base_meta');
However, this will have serious side-effects and you will lose a load of functionality. I've put a rather extreme amount of effort into the meta tags, and I can say that the meta tags SFC builds are very likely better than any other plugins around. The new 1.2 adds video and audio support, for example, which virtually nobody else has.
So I'd recommend getting rid of any other meta tags instead, and letting SFC handle it for you. Really. If you want to modify just some of the meta tags, you can use the sfc_base_meta filter to modify the array of meta tags as they are output to the page.