Verify and double verify with the applicant that the information they have provided is correct and that all income is verified and all adults will have a background check. 

Looked up hotels and I see $350-600 per room per night for 2 adults and 3 kids.

Do you screen all adults in the household or just the person paying the rent? 

Myself, I've made millions with Section 8 properties, but every day you need to suit up for battle to deal with tenants who have no sense of adult responsibility.

You don't think grown adults who cannot (or will not) pay for their own housing are statistically more irresponsible than grown adults who do pay for their own housing?

You may come across pushback with having co-gendered units so as you grow I would suggest leaving room to have unit(s) that are male and female only for those who are more comfortable with living with others from the same gender. 

You don't want sketchy areas because you will get crappy tenants and smart females won't want to live there (too dangerous at night).

For example, I mention that every adult must pay a $30 application fee, pass my credit/criminal background, make a combined income of 3x the rent, and whether or not the property accepts pets.

My personal example is a one bedroom condo I’ve held my entire adult life - and this is in a top tier market - Dupont Circle neighborhood in Washington DC.

Any healthy adult with an average IQ is capable of paying off $10,000 in debt and saving at least $30,000 in two years.