However, if this total income number is negative it will count against you like any other liability would (think car loan or other mortgages with no rental income or credit card min monthly payments/etc) against your DTI.DTI is typically maxed out around 45-50%, so half of your monthly figure so if you make 10,000 gross per month your max liability at @50% DTI is 5000 a month max payment.

However, I can't find half of the owners.

I had a tenant who paid late every single month, like she’d usually give me half early in the month, and the other half after like the 20th, I literally didn’t care, she never missed a payment (she did abandoned here dog in my garage after she moved, but that’s a whole different story) but as long as you are getting paid in full every month you should be happy lol. 

I've got a 5 month old and just started training for a half-marathon soI'm somewhat sleep-deprived and my brain isn't firing on all cylinders this morning.

We get about half of our properties from other companies that are tenant occupied so this is very common in my market. 

The $1800 does not come close to paying half of the $5400 piti.  

If your mom is ok with you owning half the house but not putting any money down then you should be fine.  

If needed, you can even offer a small incentive, like a half or a full month of free rent on a 17-20 month lease.

I get it I built half a dozen starter homes in FLA that were to minimum UBC code but they are still designed better than HFH when it comes to curb appeal.. and keep in mind your neighborhood is owner occ.. huge difference than subsidized housing. 

To be honest, if you have a solid team in place in the market of your choice, thats half the battle.