Lease Option help

[Sterling White]

I am doing my first rent to own on a recent property purchase. Would like some insight from others who have had success with this process

1.) How do I pre-qualify prospective buyers (lead calls from my "Rent to Buy" posting)

2.) Structuring the lease -600 rent with 200 credit to purchase price/option to purchase amount of 2k down-

3.) Do I need to go through mortgage broker to make the process move along smoother?

Feedback is greatly appreciated