Need a WordPress Guru to Debug and Make Responsive an existing site

We have a working a bilingual Persian/English WordPress site (art and culture charity). Firstly we want to make it a responsive site with more or less the same look and feel as the current one. Secondly we have a number of problems with the current site which need fixing and basically making the site updated and standardised with the current practice. The site was developed out of a Flash site and still carries a legacy slider and animation. Some of the design for categories and sub categories are also hard coded and need to be looked at. A new bug (mis-directed or mismatches between English and Persian pages) has also appeared recently when we tried to migrate the site to a dedicated WP server.

Please do not apply if you are not a wordpress guru or have not worked with bilingual sites. I will provide further details to serious replies.