(my house was underwater completely except for the crest of the roof) ALso, the city wasn't letting anyone back on the island (even owners) for like 14ish days (I forget the exact number), so ALL of the non-raised houses were full of mold by time anyone was allowed to go in and start doing things. 

New hot water heaters + roofing.

We replaced the old roof as part of the project and had the interior walls primed (with Kilz) and painted. 

The mold must be terrible and I expect that the furnace is completely rusted out.There's about two inches of moss on the roof and the porch.Considering that they are going to need to pay 5k in property taxes, get a quiet title, pay a REO realtor, and get the place up to code for showings or winterize, is it possible that they won't show up?

It would likely depend on state regulations that may dictate whether an owner/operator could live under the same roof as residents ( a casita or guest house may solve that issue).

The house needs a roof and potentially a new septic system installed which they also considered. 

Hey guys i need you help here and i need some of your experience pls...I'm on contract of my first brrrr with hard money loanAnd i want to know thatcif i change the roof now and fixing the crowl space That will cost me to do both of the things around 20k I running the numbers and i can get the arv that i need buy my question when the aprizel coming after we finish to renovation the house with this to major fixing issues that he coulcaite with this 2 major fixing to his numbers for the arv or not ?

My current primary, which I have been in since last October, is in need of a new roof.

It appraised at $553k and the inspection showed lots of minor to moderate deferred maintenance, mainly needing a roof and some foundation repairs and a few water leaks inside that need addressed.

I repaired some interior work costing me about 7k and the roof which is about 18k.