Wow. You must really have vast knowledge on crypto currency. Actually this is my first time hearing of ethereum 1.0 not to talk about Ethereum 2.0l. Thanks for sharing. This is one advantage of this platform.ETH1.0 is one blockchain. ETH2.0 will be multiple blockchains shards connected by a manager blockchain beacon chain that also handles ALL the mining which wont be mining anymore due to the switch to staking. ETH will live in this ecosystem of chains, and you will be able to swap it easily between all the chains. No separate coins. The beacon chain does not allow smart contracts because its job is chain management, not having user content. Smart contracts live on the shards instead. ETH2.0 wont be introduced all at once. The plan is to launch the beacon chain first, but without using it for anything. It will gradually develop more features, and shards will be introduced slowly over time. ETH1.0 will be deprecated once ETH2.0 is far enough to replace it.