If I ,for example, create a page like "http://example.com/?favorite=all", will my page be indexed in the Google search results?
Yes unless you use your .htaccess file to rewrite the URL to something like "http://example.com/favorite/all/"
Yes of course it will be indexed. For example if u search google with 'ecards.jolchobi.com' u'll find pages like ecards.jolchobi.com/chobi.php?c=xms&p=031.gif&t= is indexed.
Yes Google will index be able to index it. Its upto you to make it a friendly URL, less parameterized, more keyword optimized. Rewrite your URLs on .htaccess file. Google doesn't index URLs with /#!/ " in it.