Hey @businessbackpacker,
Sorry for the confusion. You don’t need CSS to fix your featured image. The reason the image is small in single post like the screenshot below is because your image resolution is small.
Other themes automatically will make the featured image span the fullwidth of the content area but not in X because if it does, your image will be blurry or pixelated like this:
The solution for this is to upload a higher resolution image. Preferably 1024px or higher. But, for your setup now, 800px width will do.
Regarding your comment form, I see the issue in your site. I suspect one of the third party plugins is causing this as there’s no known bug related to comment form and I also could not replicate this in my test site.
Could try testing for a plugin conflict? You can do this by deactivating all third party plugins, and seeing if the problem remains. If it’s fixed, you’ll know a plugin caused the problem, and you can narrow down which one by reactivating them one at a time.
Thanks.