All right ! Great to hear from you.
However point 1 (security) is not just a matter of distribution, it is also about POW which right now is a more secure (albeit energy intensive process).
Absolutely granted
That is why I also think you are wrong on point 2. A switch to POS is by no means going to be trouble free - indeed I suspect it will likely cause another split in the ethereum community.
I have been hearing about other currencies taking the gateway position for some time and yet it has never really happened to any significant degree.
Agreed to some extent. I never thought it could be trouble-free and I also think it can lead to a new hard fork. I believe though, that gradually a new gateway (or PoS coin adoption) can become a reality, and possibilities like a Bitcoin or Ethereum hardfork will only serve as triggers to accelarate such adoption.
Anyway, as usual, you have sound arguments. We can't predict what is gonna happen for sure, we can only look at probabilities, and all of your points have helped me to form my expectations about it.
Cheers !