All of those academic style manuals disagree on various points, and they leave a lot of questions unanswered. I prefer to use a style guide that is primarily written for secretaries, called The Gregg Reference Manual. If I am required to conform to the MLA or the Chicago manuals (which mainly gather dust at my house), I check them for the most obvious features of a paper, but for general issues of language use, I think you can safely flush those manuals down the toilet. I had gotten frustrated with those manuals long before I went to graduate school, and I never used them once during my studies. All I did was write according to what I thought was a correct style, and then check the papers in academic journals for things like bibliography formatting, etc.
A note about style manuals: When I worked as a proofreader in the communications industry, my colleagues and I used to make everything conform to whatever we thought was a reasonable style, with some idiosyncracies for individual client companies (V-8 for Ford, V8 for GM, etc.). We kept five or six different style manuals in our office drawer. When a writer at the company did something in a way we didn’t like, we would go through all the style manuals for “proof” that he had done it incorrectly. Sometimes almost all of the style manuals agreed with his usage, but if we didn’t like it, we’d pull out the ONE manual that agreed with us, take it to him, and say, “Look! The style manual says you’re doing this wrong.” Any style manual we chose that day was THE style manual. The writers would always obey us, because we had shown it to them in THE style manual. They would have no clue that there were five other manuals in the drawer that supported them! :twisted: