Were not the primenode rates changed in which the primenode 10 and 20's also got 100%?
Were the keys changed with the stake rate change or was it just a change to the stake rate associated with each key?
New keys were
not issued, it was a change in the stake rate associated with the keys
https://github.com/PaycoinFoundation/paycoin/commit/cf1eaf6a485281a9150e0b21e6232c0830d8697bShouldn't there be built in protection to prevent more than one wallet from staking with the same prime key?
Yes, it's called decentralization, having the same stake rate for everyone.
So, Prime Node managers have agreed and are currently NOT compounding their stake. If these keys are legit and the coin is not forked anyone else can compound stake at