Hi,
1. For that, you can change the keyword logic. Try the “AND” or the “OR” logics, those are for fuzzy matches, without matching the whole keywords.
2. I’m afraid this is way beyond the plugins capabilities. Basically anything the user enters is considered a search against phrases within the selected fields. Regocnigzing meaning beyond questions and finding mathes intuitively would require some sort of AI. However, if you use the “OR” logic, then matching even some of the keywords partially is sufficient for a match, which sort of can bring up some of the desired results.
3. This definitely requires custom coding. It should not be too difficult though in my opinion, if the keywords are already highlighted.
I might be able to suggest something, but I need a bit more information. Can you please send me a link to a page where the search shortcode is active? Also a search phrase I should try that brings up a FAQ where the keyword is highlighted within a section, which should be opened. Thank you!