DEFINITION:  Under joint and several liabilityor all sums, a claimant may pursue an obligation against any one party as if they were jointly liable and it becomes the responsibility of the defendants to sort out their respective proportions of liability and payment.Meaning the landlord can go after both people or just one person.. but either way each person is responsible for the other's actions. 

A sales agreement implies contractual agreement, and a lease option with the option payment applied to sales price - all three of these can create an equitable defendable interest in the underlying property. 

Who is the local champion of networking in your opinion?

As others have said, you are not REQUIRED to tell them the reason - and I would advise against it as at the very least will put you in a position for extended dialogue trying to defend your decision, or worse an accusation of discrimination.I would not lie and tell them someone else was first. 

Some posts defend that their accountant says the expenditures/deductions are fine. 

It's up to the defending attorney to argue against the propriety.As for an LLC for each property, this is a point that everyone has multiple opinions. 

How much will it costs for a defense lawyer to defend these frivolous cases if it does get to court? 

Denying someone forever is not only against Fair Housing rules (which can be a very costly issue to defend); it’s also not reasonable.

But, getting his with a 5 figure fine isn't worth the trouble.Landlords are fined first and then are forced to defend themselves in court.

The actual lawsuit papers must be "served" on the defendant before the clock starts running on their time to answer.