There's also a huge difference between (1) sitting down and reading the whole thing straight through in a few sittings and (2) studying the text with teachers and commentary over the course of a year.

(1) prompts a focus on the literary aspects of the Bible, which are often subversive vis-a-vis mainstream Orthodox culture, and allows you to notice dominant themes and glaring inconsistencies.

(2) carefully pushes aside inconsistencies while giving your community ample time to help you bury any contrarian impulses you inadvertently develop.

I'd strongly guess not. I suspect that most have read all of the Torah, but I'd be surprised if most have read all of Nach. Most Orthodox Jews aren't going to read stuff there unless it is in that weeks haftorah or is associated with some event (such as one of the Megillot). That leaves most of Kings and Chronicles unread as well as many of the later prophets such as Daniel and much of Ezra.