When Marie Antoinette married Louis-Auguste, Dauphin of France in 1770, who later became King Louis XVI of France, was she considered as a fully legitimate bride or was there some sort of political compromise involved? On the one hand, her mother was the Holy Roman Empress Maria Theresa, but on the other I don't recall any French Kings who had married Habsburg princesses at any earlier times. 

Did the members of the House of Bourbon look down on the Habsburgs or the inverse (or both) for heraldic reasons? Were there any explicit house rules by which French royals had to obey in such matters and at that time? (If memory serves, the Habsburgs would later list approx. two dozen families whose daughters they considered legitimate matches.)