Possible spoiler answer required: I really need to know, do Tempe and Andrew Ryan ever really end up together? Do Tempe and Pete get a divorce?

I think you should ask on Kathy Reichs spot...I havent read all of the book yet, so dunno

Yes Pete and Tempe get divorced and yes she does end up with andrew ryan which will be the same on the show with booth because he is ryan in the books.