By the way, I just told my tenants they can pay rent online and suggested they pay with credit card to boost their credit score (a particualr tenant of mine had a low score and gave me a large security deposit and that really convinced him).

Do I place my business card and a flyer in a vacant house mail box?

I have all the money needed to close, but underwriting wants to know where cash came from that I used to pay off a credit card about a month ago. $850 or so.

After receiving my 2 cards I spent the first year just normally using my cards not trying to build my credit or anything.

Then when I was a teen with my own transportation they would pay me for labor.

If it's a year or less, I would suggest getting the credit card and racking up the points.

They can also pay rent with a credit card.

I made a lot of bad decisions in college,  I started partying, racking up loans (even though I had full scholarships) and somehow still managed to max out two credit cards.

Transport issues, rental restrictions, resale restrictions, etc. 

Section 5-15(a) of the Act provides:  It is unlawful for any person, corporation, limited liability company, registered limited liability partnership, or partnership to act as a managing broker, real estate broker . . . or to advertise or assume to act as such broker . . . without a properly issued sponsor card or a license issued under this Act by the Department, either directly or through its authorized designee. 225 ILCS 454/5-15(a).