Hi @alekrumkamp, great suggestions!
Here perhaps your meant static-content HTML pages? Static files (images, CSS, JS etc) are cached by default, and do not require a specific page rule.
As your webpagetest link shows, more than half of the whole time was spent at the origin. If the content you create is static in nature (page does not change whether or not the visitor is logged in), you may create a page rule with
Cache Level: Cache Everything. Please search this Community forum for ways of implementing it on a WordPress site.
Also, your images are at a third-party CDN. These files are not cached by Cloudflare, and you may want to A/B test whether they would load faster if you stop using the other CDN and placed the images at your origin so that they are cached by Cloudflare.
Last, I’d suggest you add all the third-party domains your site send requests to (www.googleanalytics.com etc) as Preconnect hints. There are some plugins that can help you with that. (I personally use Pre* Party Plugin for that).