Customizing Thesis Theme & Thesis Boxes for Website (WordPress)

To provide some detail on the project: - My website is hosted on BlueHost and uses the Thesis theme for WordPress. - I am interested in customizing Thesis to fit the website's needs rather than creating a custom theme. Currently I am using the Social Triggers skin, but creating a custom skin is fine too. - There are four page layouts to be developed. The pages will include a homepage / landing page, a Blog landing page, an About page, and a template for blog posts. - I have already made hand-drawn mockups of what should go where on these pages. No design is necessary, just development. - Three major elements will be present on almost every page throughout the site: a top navigation bar, a footer navigation bar, and a sidebar. - These three elements will need to be easily customizable so that the content within them can be changed through Thesis rather than by editing the actual code. - The website should have a fast loading time. - The website should function well on mobile devices. - I have Opt-In Skin, which can be used to create the various types of email opt-in forms shown on the site. - I can provide all headers, text, labels, and images that are to be implemented on these pages, except blog posts as I have not yet written any. - Things I do not have: share buttons, icons, background vectors. Things that are fairly easy to acquire from a design asset provider.