Have you ever been evicted, have you filed bankruptcy, do you smoke, how much do you make, etc. 

Appreciate your advice and any expertise in this.Thanks If they both pass credit/criminal/eviction/landlord/income checks, and their combined income is enough, and they otherwise meet your criteria (no smoking, pets, etc.), you can't deny them.I'd really try to get previous landlords to let you know if he's had any behavior issues. 

No pets, no smoking.

Other reasonable accommodations to consider would be visual doorbells, visual smoke/CO detectors, and allowing hearing assistance animals.

With rent subject to change... what if you start the "non-smoker" out at a lower rent rate and they turn out to be a "smoker" or take up smoking later?

Now you know their current landlord is a relative - no relative references  - denied.Also, you won't be able to tell which one is the one who smells like cigarette smoke.

Or is that smoke and mirrors for discrimination?

I have been trying to get ahold of my current tenants for almost two weeks to do a scheduled smoke detector/maintenance check on the property.

Perhaps you forgot to swap out a 9V in the smoke detector after the last moveout, or perhaps that pesky drain pan went missing.

The ones you'll hear sob stories from probably always have money for cigarettes, going out to eat and to the bars, expensive cable TV service, and a smart phone with a huge data plan LOL.