The correct answer for the Inversion from Arabesque quiz is the skill is legal for level 5 as it has the necessary 3 catchers for the downward inversion and the contact is initiated at the shoulder level (or above) of the bases. Per the recent clarification for level 5:
Clarification: Downward inversions originating from prep level or below do not require three bases. If the stunt begins at prep level or below and becomes inverted above prep level it requires 3 bases. (The momentum of the top person coming down is the primary safety concern.)
The answer to the Bonus Quiz is the skill would be Illegal in Level 5 with 1 less base. In the video the top person becomes inverted above prep level making 3 catchers required for the downward inversion, per the red text of the rule quoted above.