I don't know who should write it, but ideally, it would be someone with who can really emphasize dialogue and character interaction in a believable, and dramatically resonant way. Action has not been a problem and, by all accounts, isn't that difficult to write, at least in comparison to good character development. I mean, the problem with Spider-Man 3 wasn't that there was too much character stuff and not enough action, it's that the character stuff was handled poorly; the film clearly felt like it was better than it was in that department, and ended up coming off as overdramatic and schlocky.
I almost wouldn't even MIND a Spider-Man movie with the same ratio of character development-to-action, as long as the character development was well-written, which, in Spider-Man 3, it was not.