Help! Should I rent to these people?

[Casey Culver]

Hey y'all! I'm renting my first deal as of 3/10, yay! But I have a question, I have a mid-high end 2 bed, 2.5 bath, 1600  sq. ft. townhome that I'm renting for $1295, a good market value price in my area in Alabama. I have potential tenants who seem very serious on moving in as soon as they can, but there are a few red flags and I'd like to know what other landlords would do in this situation. 

One girl has credit score of 400, her supposed boyfriend has credit score of 650, 2 other adults will also be moving in with them, which is the height of our limit of 4 people per room, I don't know the other 2 credit scores yet but of course I'll screen. Apparently there's 4 separate incomes, so there's that, but do I need to do anything special here? Should they all still be on the lease? Should I deny them? Any advice?