(Note: I'm not a lawyer, but this is my understanding based on my experience)  A human being will need to sign on behalf of the LLC and that human will need to have the authority to sign. 

One challenge that may arise during the sale process involves third-party property management.

They should have a process for this that will likely involve probate.

. - You've got some pretty solid information above and concurrence that it shouldn't cost nearly as much as you thought, but on a separate note, I'd like to understand your situation a bit better.You are currently just looking for a Chicago property to purchase and asking the quit claim question in preparation for closing? 

But, understand the cost involved.

Many S8 tenants are getting free rent money, yet don't take the time to understand the program and dump everything on their caseworkers and landlords!

Don't ask on this thread, as most tax strategies require a good understanding of your current and future tax situation first.

It would be smart to do a full lease audit, estoppels issued, and tenant interviews.And if you are buying cash, there is nothing mandatory, since it is your money at risk. but again, physical condition inspections, understanding of tenants (they are a great source of information about issues with the property that the landlord may not know or may not disclose), surveys to understand accurate property lines, etc.

It's all noise because you shouldn't invest until you have a foundational understanding of what you are doing.

I would recommend house-hacking or partnering/mentoring to get a better understanding of real estate on your first deal.