Of course Governments would step in and bail out key parts of the financial system. They always have: although this is one of the key issues when those self-same infrastructure assets go into private hands.
I believe that the problem with an energy market meltdown could be that, unlike in the LTCM saga, the Fed cannot print oil, so that there is no limit to where the price could go.
so there is no need to "print oil". price setting could and would go back to voice brokers or oilco traders could actually talk to clients instead of staring at screens trying to make sense of ticks.
I sold millions of bbls of fuel oil without a futures or forwards market. No EFPs, no nothing.