What you describe as far as the testnet was pretty much what was done for hardfork 20. We had a working testnet that was a clone of the mainnet, did not have the full historical set of data (to keep the block_log size low), and was even getting a copy of the new mainnet transactions mirrored over in real time. There was also a testnet condenser: https://condensertestnet.steemitdev.com.
RE: Fake STEEM, SBD, witness, market, condencer and so on: Let's test steem for real from now on!