Fix a personalised gift woocommerce website with various variables not working

The client is a friend who has been let down by my contractors, but also bad communication (we thought all was well and were shocked to hear it's not been right for 6 months. I am out of the country for some time so can project manage from here but want you to work directly with the client to identify and resolve issues and train her how to use woocommerce if there are skill gaps. Issues include but not limited to; Lots of error 400 pages Lots of plugins and some conflicting with each other White screen on checkout (I could not replicate this error) Making the website more effective as a marketing tool (WPSchmush WP Optimizer, similar etc) Site is a UK based ecommerce site where customers upload photos, unique text or choose from pre-made designs depending on the item and the variables allowed. The URL is below - take the word LUXOR out of it to get the URL. [login to view URL] I will only engage with bidders who use the word LUXOR as their first word in their bid - I am fed up with autobidders who lie and say they have read the brief. You will need to communicate directly with the client via email and perhaps phone, email probably best, using my branded email address I will set up for you. Good English skills and technical skills essential and customer care.