Audio Fuse Block & wires

[chato de shamrock]

I'm putting a new radio head unit on my car and had two questions regarding the fuse block and one of the wires.

First off the fuse block. Is it a must to have this or can I connect the wires from my radio to the wires coming from the dashboard? I'm not completely understanding the purpose of the fuse block. I pulled the old radio and noticed the block with black, red and yellow colored wires running from the radio, through the block and into the dash. I'm not sure if the block is original or installed later. I did noticed the wires running from the dash were connected using some plastic ties to the wires that were soldered onto the fuse block, and the wires coming out of the opposite end of the fuse block were connected to the radio wires using some plastic tie. Looks to me like the previous owner might have put in that fuse block. If its a must having this block, can i recycle it and use it on my new radio or is it recommenced to also put a new fuse block?

Moving on. The new radio has 9 wires. 4 of those go to speakers then theres a blue, yellow, red and black. I understand where those run to but the 9th wire, an orange colored w/white stripe, is where i'm stomped. It indicates it goes to the car light control switch. My old radio doesnt have this wire so I'm not sure where I should hook this one up to. Any suggestions?

I'm sorry if these questions are basic stuff but this is my first attempt at hooking up a radio so i'm learning as I go, and thanks for your time guys.