Yes, RCA cable runs that long are a bad idea since analog video is more or less no longer included on equipment going forward. For audio, there would be no reason to run RCA cables anywhere else in the room except perhaps for the sub, since all the gear requiring analog should be in the same location. Run HDMI, CAT5 or CAT6 cable whether or not you need it now, and UL/CL rated wiring and you should be fine.