If the person truly cares about the child yes, but some people mistreat children simply because they do not belong to them. I am very curious though, would this stepparent step in if there was no money involved are would the U.S. Government be the co-parent. Just wondering.
Yes if he taking care of him or her he should be able to do what necessary to keep his family in line. First of all the biological parent should let the children no that you not going to disrespect him or her at all. I have step children that are so disrespectful it a shame. But there mother not raising them they are raising there self. My husband try's to do right by them but they mother hates that he got married to me without even knowing me. But oh well I don't have to deal with them anymore I can save my money now. Didn't appreciate me when I was doing for them. But that's there mother fault cause I know I'm a good step mother.
If they are taking care of the kids as their own then they should be able to discipline the children as their own.
I am a step parent and I love those boys as my own when you're a part of a child's life step mother/father don't matter it will come a time when you will need to discipline a child My step sons are grown and we still have a good relationship "Yes ,I discipline them when it was needed and I still love those boys as my own there father and I have divorced and the boys still love their extended family
If they are supporting them n don't abuse them yes .
because you may never know what might happen, I have 3 step child i do all i can for them.