There are some people who are always afraid of something. Sorry, but you seems to fall under this category. I have couple of friend like you. Be brave and enjoy life.
As to buying the property, have you heard of something called "insurance" which can cover you in case of disaster. Buying adequate insurance will buy you peice of mind.
I bought my first house (in CA bay area) within 1 and 1/2 year of coming to US. People discouraged me a lot (I was on H1). But, that turned out to be the best decision of my life( sold at 100% tax free profit and bought another house 4 years ago. this one has appreciated a lot already).
What type of federal aid do you have in mind? Federal aid in form of soft loans is usually available when a big disaster hits the whole big geographical area.