I've often heard that prepaying of rent like that is a red flag as well but never fully understood why?

The reality is that if you are a responsible landlord concerned with reducing your financial risks and you do not at times discriminate then you are not a responsible landlord concerned with reducing your financial risk.I always choose the applicant that is most qualified and as a result not only protect my business but also protect all my tenants by not putting my business financially at risk.Any landlord that would choose to select a less qualified candidate only to respect anti discrimination laws has either not understood how to screen or chooses to set very low screening standards.

Rent payment is universally understood as being due in full and on time.

Being college students, we understood what he said but didn't think he was serious, so we held a small get together and had a great night (don't think of any crazy parties, think relaxed kickback).The next morning we got an eviction letter telling us to move out immediately.

I've never really understood the fixation people have on completely smooth walls anyway.

Right on and understood.

I think you're getting some cut and paste responses that aren't related to your story.From what I understood from your original post, you are wanting to rent your home that you are moving out of.  

However, he was a reasonable person and understood how this affected me. 

I told my agent that we understood we'd lose our EMD.

They ended up better off with me then they would moving and for the most part they understood.