Hey,
I know that many in my country are doubting, there is a 1% decrease every year. However only 30 persons are disfellowshipped every year (of the total 30000 in my country).
Hm, I don't know what to say about the Satan thing: Actually I see that they are actually right, not especially about the Satan thing but about what they say: "if you seek friends and live in the world, you will leave the organisation." And there they have a point, because that is actually the thing that is happening to me. I don't believe that it is because of Satan, but because I see that the world is not as bad as the JW say. And because I am at college now, you gain a certain way of thinking that is actually against JW.
Why do they survive? Because they give a reason to people to live for: the paradise. Actually they are egoistic: serving God for their own purpose.
Eppie