So many water tightness issues appear to be already present. That thing is awesome, but it's a nightmare.
All depends on what you would consider ‘livable’ conditions. Doesn’t look like it has had maintenance for a while now, but I’m sure you can move in tomorrow.
Also ventilation. Underground spaces can accumulate toxic levels of methane/co2/etc that will incapacitate you before you realize whats happening.
Add Radon gas in much of the soil in the midwest.
a tanker truck of Rustoleum and industrial sump pumps
seriously, though I expect the rebar to be compromised by moisture intrusion