Ok, if that's the case then that solves the issue. Conman, does that resolve the rapid difficulty change issue with EMC then if that particular method is implemented to handle difficulty from the Stratum protocol side of things?
Edit: Although I don't fully understand these scenarios described by you, I think understanding of ^^ will give you the answer to some points. Also, if I understand some of your questions, Stratum proposal doesn't target scenarios with poolop cheating with counting shares.
It needs to... not to keep pool ops honest so much as to allow miners to verify that what they THINK is happening is really happening. It's about empowering the miners, not policing the pool ops.
No, this still does not address D.
Is this relevant though? I'm not sure I'm comfortable with this, as it flips the exploit over to the miners side (although it has much less of an impact). I don't want to issue difficulty 32 shares, have them reduce their hashrate while they save up a bunch of shares until their difficulty reduces then submit them all as valid. Again, we go back to difficulty being tied to the work sent out. Allowing it to "leak" out to other work/difficulty relationships is not the correct way to go about it IMHO.