the "+" means volume up and the "-" means volume down. the silver circle if you press once pause/plays ur music/movies/sounds. click it twice and it will skip to the next song. and press it three times it will go back one song.
Maybe, depending on what you mean by "phone cable." Those intended for home use probably won't work (the connectors aren't really even compatible), but those meant for 8-pin office phones might work....
For a short cable run, an AV cable with one video and two audio connectors will work fine. Audio cable is not the correct choice for video signals but most short AV cables don't use video cable for...
CAT7 is a cable standard for Ethernet and other interconnect technologies that can be made to be backwards compatible with traditional Cat 5 and Cat 6 Ethernet cable. Cat 7 features even more strict...