Looking for Critique and Advice on Website

Greetings. Our website https://thewebandi.com is hosted at WordPress.com. We took the trouble to select a nice premium theme and develop a lot of new content. The site’s premium theme fails all validators. I thought that paying the money and the vetting process of wordpress was supposed to prevent that. We are looking for feedback on our site and also advice to find out if there is any way to have valid HTML and CSS on WordPress.com hosted sites. Our clients have different themes and these are also full of invalid markup we don’t have access to.