Clearly one can mock that which exists that one does not believe exists.
One of the greatest unbelievers of them all, Bertrand Russell, admitted that rigorous logic would not permit him to deny God's existence as a proveable fact. Agnosticism was as far as careful thought would permit him to go.
At any rate, the Boy Scouts is founded on an implicit belief in God. To contend one should be allowed to participate while expressly rejecting the existence of God is PC illogic taken to extremes.
No. One can only mock those that believe. It is still not possible to mock that which is not. Mockery requires the appreciation of the target.
No. That's why one puts it forward as a disprovable theory. A theory has not yet been shown to be false. All that is needed to refute this simple statement:
There is no God
is to drag a God out from under whatever rock She might be hiding under and prove It exists. Bertrand Russell was merely stating the obvious, that you cannot prove a negative.
As for the rest, I never once said that atheists should be permitted to join the Boy Scouts. Last time I checked, the BSA was a private organization, with the freedom to set it's own rules of membership as it pleased. Atheists shouldn't whine about not being able to go camping or whatever since they're not willing to lie to join up. If the atheists have the equal freedom to create their own equivalent Boy Scouts Without God if they want, no one is stopping them.
I agree fully with those that support the Boy Scouts exclusionary stance. It's no one's business but theirs.