Aloha micka,
I guess I'm not following you.
Place your activation cards in the for "best" direction sin your room. It doesn't need to be a wall, they can sit on or behind something.
So the entire bedroom is yours to work with, or is a shared dorm room type of thing?
Having something in one of you personally "not favorable directions doesn't activate that direction -those "less favorable" directions on a space feng shui level also represent other positive aspects. Check out Level One, Page 13. Activating the NW for one of it's attributes listed there does not activate theft/loss for you- you are activating the energy with intention at a different level.
Much Love, Shawn