DSD is 15 and lives with us full time. Her dad is the one who disciplines her and sets the rules up for her.
If you want a meaningful relationship with your dss, you need to stay out of setting the boundaries for him, regardless of how much it goes against your beliefs. If his dad sees no problem with all the things you describe, and you keep on insisting on dss following your rules, your house has a great potential in turning a war-zone run by a teenager who does not understand why in the world he has to listen to a woman he did not choose to be his mother.
I speak from experience,
although I am lucky since DP and I have similar views. At the same time, when we disagree I have learned to let it go, because first and foremost dsd is HIS daughter, and only THEN she is my stepdaughter. She cares for me, sometimes she even listens to my advice, but by no means will she accept me acting like her parent. If I came into her life when she was 2 or 3, things could have been different. They are not, though, and we made it work because I put aside my personal beliefs on the amount of tv a child is allowed to watch, or the amount of freedom they are allowed to have, or the harshness of the consequences for their actions they have to accept, and allow my partner to raise his daughter as HE wants to raise her. Guess what? She's turning out alright. A few bumps here and there, but I think she is growing up into an amazing young lady.
Trust me, it's the best way.
The alternative? Your DSS will resent every rule you set (reasonable or otherwise), he will never learn to trust you, and you will never be able to have a meaningful relationship with him. I really don't this would be the best way to help him. I think stepparents are there to love and support the stepkids, and be there for them in the time of need. We are there to do the fun things, and to support our partners in their decisions. We are NOT there to set the rules and boundaries for the kids,or to make major decisions. The day I realized all of this, our household began to feel right, and letting go didn't seem like such a big sacrifice any longer. It's worth it. Try it.