Responsibility in teens?

You are doing the right thing, if she can not be trusted (which she has proven she can't) to take care of your camera then you simply don't lend it to her. I would just explain your reasoning behind your decision and maybe offer to help her make the video, but under no condition do you just hand it over to her. She is not entitled to anything, and based on what you have said she definatly does not deserve it. I do want to say though you need to start demanding responsible actions out of her, i mean keeping her room clean should not be something she gets to choose to do at her age, you demand it be done or no leaving the house with friends till it is. As far as how she treats her things, simple, i would not buy her expensive things, i would make her buy them herself she maybe she will value taking care of it more. I mean honestly, she is not a child anymore she is a growing young woman and needs to start acting that way.