The cost of a Hippogriff should be 145 points. Early printings of the Bretonnian book incorrectly listed it as 125 points, however later printings have corrected this error.

Yes.

It pivots from the back rank.

No.

Yes, these Virtues only effect the knights that they are given to.

No.

No, the unit must counter-charge

After the Virtue's extra attacks are rolled.

The Green Knight's save is in fact a regeneration effect, and can be taken whenever he dies, no matter what killed him. It doesn't prevent him from dying, it just keeps him from staying that way.

The latter - the Bretonnian player is assumed to have demonstrated sufficiently chivalrous behavior already.

No and no Victory Points.

No. Even though one might still need to roll 2+ to hit and 2+ to wound with an autokill weapon, the rules of the Tress forbid the use of an autokill weapon regardless of how the weapon actually slays a model.

The Direwolf FAQ Council Interpretation could not decide this question based on the published rules. Roll a D6 to decide if the magic of the Tress defeats to-hit and to-wound penalties everytime it occurs, or come to an agreement before the game starts.