My personal recommendations for racing is Need For Speed Shift which is spectacular and just an awesome game. You are not racing around a circular track over and over but you race all over the world. NOVA is an amazing First person Shooter which is sorta like Halo. A must.
Read reviews on TouchArcade.com among other sites that have iPad reviews. Check out Appshopper.com for charts of iPad games. Finally check out YouTube for video gameplay, advice and reviews.
Sorry I don't have recommendations for your other apps but plenty here will steer you right