Yes very worried because it means they can control the network and even modify the protocol to make it a fiat, create a zillion coins, etc.. Some argue that they can't do that because the Bitcoiners will fork to a new chain. But these Bitards forget that the masses don't care about Bitcoiner idealism. They just want to buy their pizza. See my Transactions Withholding Attack thread for more explanation on that. Once the masses are already using one fork, they won't switch. The controller could run the fork well enough that the masses are happy, even while creating more coins, etc. Exactly like fiat. We go right back where we started.
That is nonsense. It isn't that other nodes would fork it is that 100% of the nodes would simply reject a chain which violates the rules like create a zillion coins.
Hey you forgot that > 50% of the mining nodes will be controlled by the attacker.
If you mean non-mining nodes, they have no protocol interaction with creation of coins. Duh!
You are nonsense.
It doesn't matter if a single miner does it or someone with 99.999999999999999999999999999999999% of the hashpower. An invalid block is invalid regardless of how much hahpower created it.
Miners simply force a consensus when the network is split on the status of transactions. All node (as in every single full node on the network regardless of if they are mining or not) independently verifies all transactions and blocks. An invalid block is simply invalid.
Your claim is simply false and shows a lack of basic understanding of the system you are trying to "fix".
https://en.bitcoin.it/wiki/Weaknesses#Attacking_all_usersIncorrect. You are Dunning-Kruger ignorant on this issue (I recognize you are reasonably knowledgeable on Bitcoin overall).