One question: how would you prevent 51% attacks during step 7? There will be a time span until most miners are mining this so that the network would be vulnerable, or not?
Technically, the organization distributing the change would be the one attempting the 51% attack. If it succeeds, then it demonstrates the protocol is weak in the first place and that 51% can be done by a small group of individuals.
I do not understand. Even the safest protocol cannot withstand a 51% attack. You could bring Securecoin down that way.
The goal of any 51% attack is to control the protocol, for evil, for good, it doesn't matter. To change the protocol, you just need 51% control of the mining. You are hypothetically executing a 51% attack by getting 51% of the miner's power to follow the "BTC 2.0" protocol. If it can be done for "BTC 2.0", then it could be done by a government or criminal organization.