Wordpress - DB Clean up and Site Performance Optimization

Site is WP with a professional theme. Candidate must have solid background in DBs, WP and Speed Optimization experience. There are 2 main tasks. 1/ DB Clean up. This site has been worked on by a number of developers here and somewhere along the line the DB got messed up. Now I can no longer import/export the DB so I cannot do backups. I want several of the current unused DBs deleted and I want the working DB cleaned up so I can import/export with no trouble. 2/ Site Performance optimization. This site is slow. It is a UK domain so I am mostly interested in performance from the UK/EU. (a) Install W3 Total Cache (b) Leverage Browser Caching according to Google page speed insights (c) Enable Compression according to Google page speed insights (d) Optimize WordPress database. I need to see the speed optimization improvement in testing tools such as Google page speed insight analysis, webpagetest (dot) org and pingdom.