'Request' is used in this sentence as a noun (basic nouns include people, places, things, or ideas).
'Be' is used in this sentence as a verb (verbs name actions and also show being or appearance).
Yes. Just because your mailman reads others mail does not mean that all mailmen do the same.
The theme is a story's underline message or big idea/ plot
culture can mean many different things like how peoples dress, eat, religion, celebrates etc. Like we Americans we wear jeans and eat chicken , burgers and some of us believe in god while some believe in other things . culture is very very very important to different parts of the world