Is "Sono tanto imbarazzato" acceptable as well?

So why does the drop down help suggest "a disagio" as a first choice for 'embarrassed' but not accept it. According to Wordreference it seems that the word 'disagio' tends to mean uncomfortable rather than embarrassed - so should it be suggested in the help anyway?

Why can't it be "molto"?

Why isn't "imbarazzata" reflexive here, or am I missing something (e.g. a different 'object' of the embarrassment). It's unlike italian to be as vague as english!