As I have oh, 20 years of experience with this topic, I'll chime in.
Without trying to start an argument with anyone: Renting Sucks For The Renter. IME, 80% of the time you will lose some portion of your deposit simply for normal wear and tear, even though that's explicitly allowed and understood in most leases as normal and expected. Some landlords/apt complexes literally will not allow you to hang a picture on the wall without incurring a $1,200 "repainting fee." I have lived in one such apartment complex in Omaha, Nebraska. Others are OK with nail holes/wall anchor holes as long as you at least patch/spackle them before you leave.
When you rent, you have to EXPECT to lose your entire deposit no matter what. At least in Texas, the typical Texas Association of Realtors (TAR) lease legally allows the landlord/property owner to return all, some or NONE of the deposit and the language talks to wear and tear, damages, etc. Very subjective and biased 100% to the landlord.
That said, the changes you've made to make that room a theater are entirely reversible. Hollow wall anchor holes can be patched easily. If you have painted the room a different color, expect to repaint it to it's original color when you move out. I don't agree with others that you have to check with the landlord first before painting a room or swapping out a light fixture. I added a ceiling fan to a room in a house I rented and left it there when I moved out. The home owner got a free ceiling fan. Same with $300 worth of fluorescent light fixtures I put in the garage. Too much trouble to take them down, so I asked the owner if it was OK to leave them. I got a "That's fine." email reply. And why not FREE STUFF. You simply must be prepared to PUT IT ALL BACK TO THE EXACT WAY YOU FOUND IT when you move. Save the light fixture you took down, save the crappy $2 shower head that was in the bathroom and take your $50, 9-setting Moen shower head with you, etc.
True Story: In the apartment in NE, I mounted a small fire extinguisher on the kitchen wall. Tiny thing about 12" long. I forgot to take it down. Landlord charged me a $50 "accessory removal fee."
After 20+ years of renting, I finally bought a house last year. I could not be happier. Good luck to you!