Does google allow for iframeing or customizing it's search results? No. A new search engine that has a API/plugin for 3rd party websites so that websites can integrate a global search engine into the website like google integrates websites' content into its instant answers. There is room for innovation here when 3rd party websites get creative in displaying global search results in different ways simple or complicated ways. If there are Ads in results, the website gets paid a % of the ad revenue that the search engine made due to the website embedding it's results.
Search engine's are high margin business, so they should be able to share 50% revenue with websites.