What is the indirect question of: are you coming to the party today?

It would be somethingt like: (Noun) asks/wants to know if you are coming to the party today. The indirect question is embedded into a main sentence. Usually, questions are embedded by phrasing them out in a noun+verb+object (or predicative) structure (many times after if), instead of the direct question structure which is auxiliary+noun+verb+object (or predicative). Thus, Are you coming to the partytoday becomes (Noun) asks/wants to know if you are coming to the party today.

taking into account that a theme is the central topic a text treats and can be developed through a story, play, poem etc. the following are themes that can be further developed:  

my best friend jeffrey has many unusual interests. (the story could be about each of the unususal interests)

once a man gives his soul over to evil, he can never go back. (this could be a saying or a proverb)

the three sheepdogs lay around the yard all day. (it could be developed detailing how each of these sheepdogs lay around)

a priest's collar has an unusual effect upon people. (it could be developed detailing the different effect upon people)

innocence is a powerful force in a world full of corruption. (it could be developed detailing how is a world full of corruption)

king lear is a play shakespeare wrote later. (it is just a sentence and doesnt give any idea or topic to be discussed in details.

evil often wears the disguise of innocence. (this could be a saying or a proverb)