This looks brilliant to me. Feels like this would be natural development for Bitcoin.

• This fixes the 51% attack problem.
• Increases the general reliability of the system as mining centralization risks would be gone and there would be an incentive to run a node.
• Normal nodes could also show their opinion about soft forks.
• Hard forking would be a lot harder, and it would be easy to see what actual nodes (with bitcoins) are "voting" for.

I think the best way to implement this scheme would be to change as little as possible of the current system. PoW blocks interval could be kept at 10 minutes target with same block & tx fee rewards as of today. PoS blocks could be made with with 10 or 20 minutes intervals. It would decrease the block interval slightly. PoS blocks would earn only through fees from the transactions they include. I heard it could be possible to do this without the need of keeping staking coins online, too, which makes this secure too.

With this scheme there could even be a possibility to implement properly working mechanism to adjust the blocksize limit. Nodes, which currently pay the costs of the network, would be able to vote for their preferred blocksize limit, or adjustment.

Please let me know if I fail here.