Hi you,
#1. The css on the website includes the CSS from the wordpress core, the css from the plugins installed on the website, and the css from the theme we call.
You can only delete unnecessary plugins to remove the css load from this plugin, some other css cannot be deleted because it may directly affect the website.
To optimize these css, you need to install the plugin to cache and compress these css to reduce the file size and collect it into a single css file.
#2. Your site conflict with Advanced AJAX Product Filters for WooCommerce plugin, I deactivated this plugin and It’s back to normal.
#3. Ok, I resolved this issue, please recheck.
#4. Please install Yoast SEO plugin to fix this issue.