Wordpress themes & plugins expert

Hello, I'm hiring Wordpress developpers to help me with many project I have. I have many projects to manage, so I will probably hire multiple candidates. The job is to create and manage Wordpress themes and plugin. Most of the time, we will have to subtheme a premium Wordpress theme. Sometime, we will have to do PSD to Wordpress Theme from scratch. I also need my developper to be able to write plugins and codes. This is an ongoing position, as I will have many other upcoming projects. THE IDEAL CANDIDATE : - Write clean, modular, robust code to implement the desired requirements with little or no supervision. - Have strong communication skills, proficient with English, and confortable speaking on Skype (good internet connection required). - Required programming languages : CSS, HTML, PHP (Wordpress), Javascript (Jquery). QUESTIONS : If you want me to really considerate your application, please answer the questions below : 1. Do you have any open source project ? Please provide links. 2. References : What other startups have you worked with ? How can I contact them ? 3. What is a "hook" in Wordpress, and what are the 2 main types of hooks, and the difference between them ? 4. If you see a new function in a new theme (example : "wp_list_filter()") how would you figure out what it does ? 5. If a client wants to exclude some posts from the home page, how would you do this ? 6. If a client wants to display a widget only on certain pages, how would you do this ? 7. Have you used premium themes before ? Can you tell me which ones ? And how did you customise them to fit clients needs ? 8. What is the best way to customize a premium Wordpress theme (bought on Themeforest) using CSS ? 9. Let's say you want to use CSS sprites. How would you create a "previous" button using this sprite : [login to view URL] ? 10. What are the steps you would use to optimize the speed of a Wordpress site ? 11. If I have an emergency on a sunday afternoon (a big BUG on a website that need immediate correction), how long would it take to reach you ? 12. Finally, what is your Skype ID if I want to contact you ?