The 49% may solve a block BUT that block will be ignored by the miners in camp "A".
That's not the current behavior, and that behavior is not part of gmaxwell's proposal. Blocks won't get rejected/discouraged for not including transactions. All blocks just need to include an extra "proof of validation".
Hmmm.
Under gmaxwell's proposal, the miner would need to include exactly the transactions specified by the person who verified that the transactions and the previous block were valid. So if blockchain.info published a set of 10 verified transactions, the miner would have to include all 10 of them.
Specified by whom? The person who solved the last block? If so why aren't the transactions in their block?
Anyone could publish lists of transactions that should be included in the next block along with the necessary "verification proof". Bitcoin nodes themselves could publish lists using a new network message.
When there are conflicting lists?
The miner could choose the list to use. Someone could even publish valid lists that are always empty, though rational miners won't use these because including a transaction is almost free.
You're misunderstanding the proposal. Anyone who is verifying the chain can publish a list. Lists can use any fee rules. For example, Bitcoin Block Explorer might publish lists at /q/getValidationProof/minFee, which would only list transactions with a fee above minFee. Under this system, dumb miners would be able to choose essentially arbitrary fee policies; they'd just be forced into mining only properly-verified transactions and blocks.
I'm not getting this proposal at all.
First... these tx-lists can be published by anyone verifying the chain? Bitcoin nodes can publish lists? Just any ol' node can do that? Considering the prospect of malicious nodes trying to crack this new feature, isn't that tempting fate, unless such lists can be ignored? And if they can, what's the point of having them?
And then, miners get to choose which list to use. So why wouldn't a miner just publish his own list, then immediately use it?
I'm failing to see exactly how all this is supposed to realistically handicap a miner and "encourage" them to put transactions into their block.
And if it DOESN'T do that, then what's the point? What is this "proof of validation" supposed to do if it doesn't result in transactions being forced into a block?
And if it DOES force transactions into a block, but I produce a block without those transactions, how could my block NOT be rejected?