Hypothetical Two, very similar to the one you described: QB's arm is moving forward with possession of the ball, defender swats at QB's forearm but defender does NOT make contact with ball, ball flutters in the air and then lands on the ground. In my opinion, this should be simply based on physics....
In all of the scenarios I can think of, the question of "intent" can and should be irrelevant. The primary keys are "is the thrower's arm moving toward the opens goal line" and "is the ball moving toward the opponents goal line." Once these two factors become primary, the question of intent no longer needs to matter at all.
All we have to do is slightly change the Russell Wilson play to show how this could lead to the same type of controversy that arises from the Goff play.
1. Let's say that there is a RB/WR close and directly in front of Wilson;
2. Assume further that there is clear intent by Wilson to throw the ball to that receiver. The QB is looking directly at the receiver, begins his throwing motion towards the target. There is clear "forward" motion of the QB's hand towards the opponent's GL.
3. During QB's throwing motion, however, Aaron Donald grabs Wilson and violently spins him around, causing the pass to travel sideways or backwards when it leaves QB's hand. AD never makes contact with the ball, he is only grabbing QB around the waist.
Under your rule, intent is irrelevant. We're supposed to ignore Wilson's clear and undisputed intent to throw the ball forward to the RB/WR. Since the key factor is the direction the ball travels, this play would become a fumble. But, why is it "fair" to the offense for this to be a fumble?
The way the current rule works, it is identical to the analysis for intentional grounding. Would it be "fair" to the offense to call this play an incomplete pass, but penalize the QB for intentional grounding? IMO this would be contrary to the purpose of the rule, because it is clear that Donald's contact is what caused the ball to go in a different direction; the ball wasn't grounded "intentionally" by the QB.