What are some things government can do to make sure the people, not the federal government gets hurt by financial collapse?
Externalize the costs to the taxpayer.
Two letters: Q.E.
Financial collapse and credit breakdown always hurts those lowest in the economic higherarchy the most as these people have the least wealth in physical assets. The government takes a huge hit as it must get rid of all of the people taking its graft as it focuses its graft on keeping the security apparatus in place to protect themselves from the mobs of poor. But I have never heard of a government that ceased to exist.
In all the collapses I have ever heard of have been inflationary collapses where the rate of money creation gets so high that it can not be used reliably as a medium of exchange thus forcing people at higher amounts of wealth in assets (This includes abilities) to use alternative currencies in addition to barter and lower incomes to use barter. Of course those who are extremely rich have already changed from currency to other assets by the time this happens.