Structure the deal which works out best for you and the seller - that may be a lower sales price, that may be the owner carrying paper on favorable terms in exchange for a higher sales price, or something different.  

A working class area.My question is that the property's green card expired on May 25, 2017 with 7 violations (we obtained this information through due diligence and not from the seller). 

I am really looking for a combination list targeting motivated sellers with more than one motivation to sell.

Any recommendation on how I can make this deal work with a difficult seller?

It's hard to say, if your son has an agent have his agent reach out to the sellers agent and find out what is going on.

When I’m ready to use my own money to purchase a property from a motivated seller, will the bank allow me to take out loans if they see that the funds that I have saved up came from RE investing?

I may missed a deal but at least I have talk to the seller.

Thank you in advance for sharing your expertise.  I'd like to buy a residential home for myself but I'd like to see if I could get owner financed, either whole or partial.  I am thinking to provide two offers, one wit...

The few properties I own in Mascoutah I purchased awhile back from very motivated sellers and they were in pretty rough shape. 

With regard to your specific question, I am a huge fan of paying cash to sweeten your offer (seller's don't like contingencies), and to speed up the process.