Black piece’s name and functions?

I’m a brand new kayak owner and am just learning about them. These black pieces are on my Tamarack. I know they are primarily used to attached the bungee straps, but can they be used for other purposes? Can they handle some torque or weight? I’d like to use them to help align a no drill pulley system, but not sure if it’s safe. Also, they move around slightly, is that normal or do the screws need to be tightened? Thank you for answering my noob questions.