You facility seem very similar to mine. In my facility many of the direct care staffers (dcs) have been working there for a very long time and they are very resistant to change. Just be respectful to each other when ever you are delegating a task. It is hard to draw boundaries esp. when you are working with interdisciplinary teams. Before jumping on anything, I always take a step back and analyze the situation. I ask myself "How does their action effect the resident medically". If the resident is positioned improperly, I would show them how to do it properly and try to fix it. Now if the dcs is being uncooperative or talks back at you, I would talk to their direct supervisor and "write them up" is what we call it. Remember the chain of command in nursing school. I would email my statement of the incident to their direct supervisor, and cc it to my Unit Director, DON, H.R. Once you have it in writing it is official. Luckily, in my facility my complaints never went beyond the Unit Director (an RN too) who took care of the problem right away. Our UD knows that the nurses run the show, and never forget that the direct care staffs are working under your license. Without you, they won't be allowed to practice independently, and don't allow unsafe practices that will come back to bite you.
One difference is that in my facility the DCS supervisor reports to the RN on duty or the UD not the the QMRP. I know of another unit at my facility where the UD isn't an RN and boy it makes a lot of difference. Good luck