Who's the speaker in Rom 7?

A perennial crux in the interpretation of Rom 7 is the identify of the speaker. Is this rhetorical fiction, autobiographical, or something else (e.g. the history of Adam, the history of Israel)? I don't have a definitive answer, but I have a few suggestions:

i) We should make allowance for the possibility that Paul uses hyperbole in this passage.

ii) It may be a fictional persona. That doesn't mean it can't be realistic. A fictional persona may represent real people or real experiences. But it's more flexible than one actual individual.

iii) There are different potential readers in Paul's target audience. Jewish converts to Christianity. Gentile converts to Christianity. Jews and gentiles who haven't converted, but might be susceptible to Paul's argument. 

So it's possible that the persona in Rom 7 represents a composite persona. An anonymous fictional character who functions as a mirror. By holding up a mirror to the reader, different readers see different things. Depending on their individual experience, different readers may recognize themselves in some of what Paul says, just like moviegoers may identify with a particular character. 

We shouldn't necessarily expect the persona in Rom 7 to be consistent if the function is to sketch composite character with varied experiences in whom different readers may see themselves. Paul might well incorporate elements of his own experience in the composite persona. No reader has to check every box. Rather, it's sufficient broad to cover a range of readers without matching every reader's particular experience across the board. The persona may intersect with a reader's experience without coinciding with their experience. There's something there for every reader.