Convert a Template to a Website

We launched our new website in March this year, transferring from an old WordPress Template to a new one. The admin of the website is managed by our small team and we've discovered a few glitches in the past month, which we believe may have been caused by us adding or deleting plugin. The problems are listed as below: - We can no longer see our regular sliders. These sit at the top of of most pages (eg. [login to view URL]) and they simply don't appear on the live website. This issue may have been caused by the JavaScript and CSS being minified by use of a plugin which was used with the intention of improving site performance (WP super cache), shorten page load times, etc. Once the plugin was activated, some of the CSS styling broke so the plugin was deactivated and deleted, which solved some problems but not others. - Whenever we edit a blog page, they disappear off the homepage and off the 'blog homepage' (here: [login to view URL]). The collection is slowly trickling away! - The Gallery in the sidebar doesn't work - the images appear as empty boxes (eg. [login to view URL]) This also could have been caused by the caching/mini dying plugin. Cheers.