Finish Wordpress site: clean CSS + add slideshow feature

I have a simple artist portfolio site created in WordPress with a customized theme. The site is working and almost finished, however I need the following things completed by someone who writes *clean and organized* code: 1. Cleanup and improve CSS on 3 pages - this is mostly perfecting page layout and might involve some editing of PHP, JS, and/or jQuery 2. Ensure pages look correct on all browsers *including iPhone/iPad* - this requires understanding of HTML5, IE quirks, and Strict vs Transitional doctypes. If it works better, an alternate mobile theme is also permissible. 3. Add ability to a) play videos and b) advance to next post, to an already integrated Supersized slideshow plugin (open-source jQuery) - I already have an example of working code from another site, it just needs to be ported to my site. Another slideshow plugin can be used, if desired, as long as the slideshow can fill the browser window without distortion, as Supersized does (note that other solutions like Slideshow Pro do not do this). 4. Enable some minor WordPress features: a) when viewing a post category, ability to show only sub-categories, b) Social (FB/twitter) sharing buttons The site must be clean and simple and perform well on all platforms and browsers, i.e. no piling-on of redundant jquery or CSS hacks that make it difficult to change styles in the future. As the existing site is quite simple, the programmer can choose to adapt present code, or start fresh with his or her own code.