question 3 - when I was confirgurating, there were recommended 2 plugins to me: 1. Contact form 7 multilingual. 2. WPML SEO. I thought because I have the normal Contact Form 7, they recommended me the multilingual version (they didn't recommend me any other multilingual contactforms), so I downloaded it. However, this got me wondering why they recommended me the WPML SEO plugin. Is it because I have Yoast SEO installed and WPML SEO is compatible with that?
Some of the popular plugins require addon plugins to add multilingual features or avoid compatibility issues. WPML detects if any of those plugins are installed on your site and recommends installing the required "glue" plugin.
Since you're using "Contact Form 7" & and "Yoast SEO", the setup wizard suggested installing the following plugins as they're required: