This room is definitely a challenge. Please don’t be offended by the use of the word chaotic, it is usually the state of a dorm room, and hard to get away from. In terms of balance, this particular arrangement is likely the best for 3 occupants. With the 2 lofted beds near the windows, and a separate bed lofted along the left side, this does allow for a "living space" in the middle where you have the sofa and desk opposite with a TV. It looks as though the closets on the right are not built in, and I wonder if they will both remain, if you have 3 instead of 4?
With 3 people in the room, a focal point becomes tricky. As you have requested ideas on how each of you can have your own style, and space, the window naturally becomes the focal point. You have said that no glue, paint, or nails, so are the items on the wall taped up? There are ways to draw attention to the windows without physically attaching items to the window or wall. One of the easiest ways to create a pleasant rhythm and create harmony in a space is to keep all the basic surfaces, flooring, bedding, wall color, furniture within a set color range. This would allow you to decorate each individuals space with accents, art, lamps etc. to connect to the individuals style, thusly creating pattern and rhythm within a harmonious whole.
The proportion and scale of this space unfortunately have been sacrificed for economy. The desks placed under the lofted beds though do help, as they read as solid elements. Adding some very large bulletin boards leaning against the walls, and oversized accessories, tying into each persons style will help with the scale. Adding some vertical interest at the windows will also help.
I hope this review has been helpful. I also thank you for being patient as I recovered from the flu this last week. I do realize that you are working with a students tight budget, so if you do chose to move forward with “Designer on Demand” questions, I will do my best to be as specific as I can with my answers to your questions. I do have some very good ideas that can be implemented for little money, just a little time, and some creativity that will make the space more comfortable, and individually interesting for you and your 2 roommates. Let me know if I can help further!
Have a very Merry Christmas and a Happy and Prosperous New Year!
Patrick Landrum RID