WordPress Expert needed for bugs

General information for the website: WordPress Site
Description of requirements/features: Site is --> http://bit.ly/1n3Xngz

I do design and create WordPress sites myself, but I am not into theme development. The site mentioned above has some issues..

** There are issues related to responsiveness, since the pages load differently on different systems, making the texts appear haphazard. Imagine a glass of water in a bowl and imagine same water in a glass, of course the water will form different shapes due to the nature of liquid, however a site cannot look weird just because opened on a mac and look normal just because opened on a normal 15.6 windows laptop or a desktop.. it need to appear uniform..

We need the site to appear same whether its 15.6 inch laptop or a 14 inch one, whether Full HD or Ultra HD or standard.. Imagine a text on slider or on the site heading coming to the second line just because the screen of the laptop is small.. what would you call it, responsiveness? It is not responsiveness, this is not what people generally expect from their site..

** Similarly, people who surf our site link above on mobile phone may not have desktop version, but should have uniform stable and beautiful mobile view of the site, and not the same issues like mentioned above

** Also check the CSS and JS of the site to make sure the site is well optimized and loads faster..
Extra services needed: Customization, Optimization
Specific technologies required: wordpress

Extra notes: please don't forget to take back up of the site, since the site is customized and the basic original site should not be spoiled while fixing bugs.. thanks