And to top it all off one of the silent investors is threatening to sue for his losses. 

really depends on how hard the buyer wants to come for the deal.. you could do nothing and the buyer just says screw it not worth fighting for .. you can play the blame game and such and see what that does for you .you can threaten the agent and see how far that takes you etc. bottom line if you dont want to sell the buyer will have to TAKE you to court and spend a ton of money to do that.

It's not much leverage, but if things get sticky you could threaten a complaint to the local MLS and to the local Board of Realtors (assuming she's a NAR member), claiming that her slowness in changing the status was unethical. 

If you are a Tenant, report it to the Landlord and demand they repair it immediately or threaten to report them to the building inspector, HUD, or whomever will listen.That wall is lath and plaster.

The county was threatening to throw me in jail if I did not turn the utilities on for them.

As far as the possibility of a base closure or significant reduction goes, whenever it's threatened, its almost immediately shut down.

Or the person who tries to negotiate a bulk rate discount, cops an attitude, and fusses about my attitude, and threatens to rat me out to my broker or the ethics board if they don't get their way?

More of a general question, but how do you all deal with being a landlord when it seems that tenants are constantly angry, looking for rent credits for minor repair inconveniences, and threatening to sue when they don't get everything that they want?

Never ever ever ever again. ever.When they want something from you, they demand immediate action (Ex: Calling at 10pm to tell me my tenants had put a small yard gnome in the flower bed outside their door, demanding its immediate removal.)But when i requested that the dry rotted outer door jambs be replaced (per by-laws stating they are responsible for "from the studs, out") It took nearly 6 months of emails, phone calls, threatening legal action, and finally petitioning to have the president of the HOA removed.

Also, I've had acquisitions guys who are the ones who actually go into the ghettos and have been threatened, gotten stuff thrown at them and one was even mugged.