.)Sairon's rules
I hope I made it clear why I belive that they aren't good without some additional rules. Basically a trading a tecnical for a huge economical problem.
.)Sairon's rules + Doubling PoW reward on blocks after a PoS block AND requireing a far higher minimumbalance for PoS
Actually, I'm not clear on why you think disallowing adjacent POS blocks would be harmful - if a POS block fails, the coin age is not lost and it can be re-attempted after a POW block has been completed - with 1 minute target block intervals, would it even be noticable?
It seems like checking the type of block that occurred and not allowing adjacent POS blocks is significantly less radical of a change than your suggested doubling POW rewards for blocks that follow POS blocks and requiring wallets to be arbitrarily large to even allow them to POS. I'm failing to see what benefit those changes would have other than it keeps people from attempting malicious activity with small numbers of coins - the POW doubling just seems arbitrary..