Hi there - welcome. We're glad you've joined us.
Just based on the dynamics and what you see already, it would be wise to get some help. This means family counseling with your pastor or a Christian counselor.
Teens are a challenge at best. I just walked through this with my kids and it's tiresome and you want to pull your hair out at times. If you're not on the same page with discipline and being a united front with the kids, they see right through you.
Have you ever had kids of your own?
If not, my non-kid friends are experts.
I still love them, but honestly they have great high ideals for how kids should be raised. Unless, they are in the middle of the battle for kids souls and what our culture likes to throw at them, they honestly have no clue what it's going to be like.
Be prayed up - together. As you will find you're on your knees all the time for this young man.
He sounds like he needs consistency in his life - both of you need to provide it - together. His dad will have to step up to the plate and be a dad - not a buddy.
Some great books to pick up together or for your boyfriend-
The Five Love Languages of Teenagers by Gary Chapman
Your Boy: Raising a Godly Son in an Ungodly World by Vicki Courtney
Better Dads, Stronger Sons: How Fathers Can Guide Boys to Become Men of Character by Rick I. Johnson
Your concerns are valid ones. You are looking at potential pitfalls in very close quarters.
It's OK to speak with your boyfriend about expectations, concerns, and how you will do this together as a couple.
In the same way, prayer is essential in this ongoing warfare. Pray hard and long. Pray for your brothers and sisters. Keep your eyes open. Keep each other's spirits up so that no one falls behind or drops out. - Ephesians 6:18