I am not sure of the exact laws in IL, but you should send any correspondence to the last known address, and if it is returned to you or sits in the box, collect it and keep it in the tenant's folder.

This will be my first property but I want to set things up correctly to start.Search for previous discussions about LLCs by using the BP "Search the site" box.

The engineered products at the box stores can start as thin as 5/16 and it that is what you bought it unfortunately explains a lot of the issues you're having.

In the little comment box I said "I'd like to do an all-cash offer contingent upon inspection, please contact me at xxx-xxx-xxxx".  

Then you or the mystery buyer went to the bank for a $50,000 loan, right?

I have fairview heating and cooling  replacing an ac u it just the dry box on the outside and if they do a good job I'm going to have them install a full ac system ok  a house across the road I'm closing on so I will get back to you.

Staples, a Office Max, or dome other big box business store may sell real estate contracts.

It may be a little sneaky, but to me it's no more so than mystery shopping a store. 

I've been happy with chinese cabinet suppliers rather than big box stores so id rather choose something like that.

Then find a market that ticks the box's, and lastly only pull the trigger if you know for sure you have a rocksolid PM in that town (super important for long term success).