He did not think I was vulnerable enough.

People in those situations are vulnerable. 

It felt vulnerable to me so took a shot with 'as-is' offer.

Please help, unsure what I can do or who else to try without paying an arm and a leg or leaving myself vulnerable for years to come? 

When you build up equity, you are more vulnerable to ending up with negative equity if the economy turns south, or the possibility of negative equity when trying to sell the property, if you need liquid cash.

Just as a good litigation attorney can pierce the corporate veil when a LLC principal makes a mistake, a good corporate/asset protection attorney can minimize or eliminate a LLC's vulnerability to piercing the veil. 

We need more people who are committed to caring for our vulnerable populations.

The way I understand it, a regular LLC in Illinois: $500 setup Articles of Organization, $250 annual fee, all properties within LLC are vulnerable to the others.

Both of these points unnecessarily open you up to vulnerability if you go to court.  

These are more vulnerable than the buyers you mentioned but I wonder how sustainable these low interest rates are?