It will depend on what the contract says.

There are some good people in business, but there are also nasty, hateful people that will cut your throat for few bucks.

I want to add that this rental business is for vacation rentals/short-term, rather than long term rentals.

I've been looking at Trulia and Craigslist to make my determinations and understand there can be a big swing depending on the general quality of the apt.Any insight/advice is greatly appreciated.  

I am not saying I agree with that percentage as it depends on the underwriting of the deal.

For those landlords who take security deposits in City of Chicago, is a separate business bank account sufficient for the security deposit or do I still need to set up the special landlord account that requires all W-9 paperwork from tenants etc?

Are you looking for official businesses, or more local mom-and-pop Property Managers?

Depending on how long they are giving you to close - you may be able to go the hard money route.

It depends on the HOA and other expenses along with your down payment though.

I want to start a business and I want to use that money towards it.