The words 'more than normal' in Furious' description is throwing me. Assuming a +1 weapon, would you be able to get the full bonus from both qualities if you were raging?
Ivery never been a fan of word games but it seems like an argument could be made based on the order in which you chose to apply the bonuses... then again, theoretically the Furious effect would already be active when the Answering ability was triggered.
They do not work together. The Furious quality specifically calls out it is +2 better than normal, while the answering quality says For the purpose of the opportune parry and riposte deed.
Normal is your base enchantment bonus. The bonus from Answering is not your normal bonus, but rather an adjusted bonus. This would also be true with another quality that provides a circumstantial bonus like Bane.
Since Answering maxes out at +5 and any magic weapon has to have at least a +1 bonus that is as high as you will ever get with that quality.