*code expert needed* make wordpress site faster + add custom elements

we have a website that is painfully slow we need an expert in wordpress and coding to go through the site and fix the code that is bogging down the site (making it slow). Right now we had to deactivae the plug ins and the htaccess file just for the site to be viewable (was getting a 500 internal error code before). It appears the problem lies within this part of the website for the error code and elsewhere for the slowness (since the site is still very very slow). You will need to fix the site so that the shortcodes we have installed works again - which showed tabs in the blog post. it is possible this is the problem too. On top of this, we need you to: 1. make text viewable in the lightbox when you hover over blog post image on the homepage. Or possibly, lightbox isn't the feature we need? see [login to view URL] for couples to see how we want the text to show. Basically, the image goes dark and text appears over it 2. delete the admin name (wowproposals) and categories that appear at the bottom of every blog post preview on the home page 3. keep the responsive aspect of the site, however we do not want the main page columns to exceed 3. In other words, no matter how big the screen is, we would like there to only be 3 columns, but each column/post should expand to a maximum of 500 if the screen gets smaller and smaller (like a mobile phone) we do not mind if the number of posts goes to just 1 (like it currently does now) we also do not want the posts to be randomly rearranged as the screen gets bigger and smaller, as it is doing now [login to view URL]