Two additional points besides what Julian wrote:
- I have made the point in the past that PoS can have slightly better market structure than some versions of execution tickets. So that is in favor of your proposal.
- On separating the roles of proposing and validating and having two pools of stake for the two roles. People have argued in favor of similar un-bundling of roles, e.g. rainbow staking. What I find potentially problematic is that it is more wasteful: In the status-quo, staked ETH is used to provide economic security, for consensus duties and for proposer selection. With your proposal, the 0x03 stake just does the last thing. So un-bundling and using the stake separately uses capital less efficiently, it’s in some sense the opposite of re-staking.