How did the government come up with that value for my property?  

There’s a reason the government specifically calls out “ rent to own “ in the Dodd frank bill a “ predatory lending practice” Save yourself a huge headache and move along with someone else

It is investigated by the lenders themselves and reported to the federal government

The good news is the government always pays, the bad news is the tenants can be unstable.

@Daniel Caraway a lot of times properties like that are grandfathered under existing zoning unless, it was an addition done without a permit or it's been vacant for a specified period of time.There are fairly explicit rules at the county level that govern zoning.

So when you're asking "can they amend the rules", what you really mean is "Can the Board of Directors amend the rules that govern myself and the rest of the HOA".The short answer is "Of course, as that is one of the jobs that you and the rest of the HOA ask them to do."

Should we attack the HELOC like I rode into Baghdad or is the a better option?

As an attorney, I represented developers, REITs, multi-national corporations, and local governments in all aspects of real estate including asset acquisition, development, leasing, and disposition.

You submit the application for the loan on the tsp.gov website, then you have to print out a two page form, fill it out with your bank info (for direct deposit), have it notarized, and then fax it in (of course because it’s the government they only accept snail mail or faxes).

Of course, I'm also a 23 year employee of the federal government.