Let me cut to the chase

[Snake~eyes]

Bob,

I agree with the majority of your post. There simply isn't enough to rule on the first two.

As for the second two, I have to say that I disagree with you, to me it looks like the first one is a definitely helmet to helmet contact. The defender does not even attempt to wrap the opponent up he just comes inwith his head down and nails him. The second one, against K. Warner looks like a legal play to me, I do not know NFL rules totally but unless the quarterback is specially protected against this because of roughing the passer then I do not have a call. It looks to me like the player was attemping to tackle the quarterback and their heads just slightly hit eachother. But again, I am not in the NFL and I do not know the NFL rules.