It's true that such a conversion (wp to elxis) would give a lot of positive feedbacks to community! We just let it go for now as there are more urgent tasks need to be done till then.
What do you mean by saying "evidence"? For example this: "A way to can put in evidence an article" makes no sense.
Highlight is already supported. Just use the "q" option in the URL for any string you want. Example on Elxis DOCs site with word "database" highlighted: https://www.elxis.net/docs/using-elxis/getting-started/installation-guide.html?q=database
I believe what you ask for is to mark articles with a special flag (featured for example) and then display these articles in a special page. Is this correct?