I agree with Bill3, there. How it would look in the future is a great topic of discussion. Many single dads are not full time parents. I'm a full time mom, so it's very different.
How often is visitation? How far away do they live from each other? He's free to move wherever if not the primary custodial parent. What would job opportunities look like for him, if ever a chance to relocate.
I'm glad to read that you are thinking through the gray areas, since he seems compatible with you.