1. I believe that blockchain "spin-offs" are an excellent tool to facilitate experimentation with new cryptocurrency features.
I mostly agree. Especially as I think real PoS are still too immature to incorporate into the Bitcoin protocol today. Even though I've been advocating PoS in principle, I'd argue against that step until PoS is better understood.
That said, I think network effects make it almost impossible for altcoins to succeed again Bitcoin. Even if we agreed PoS was better than PoW, I expect getting from here to there will be extremely difficult.
Brangdon, what SlipperySlope is proposing
is an alt-coin. The only way to turn bitcoin into a proof-of-stake network is to create a spin-off or fork (i.e., an "alt-coin") and try to legitimize it with your influence and economic power.
SlipperySlope's project development thread for Bitcoin-PoS is in the
Alt-coin Section for a reason:
https://bitcointalk.org/index.php?topic=584719.0