var ObjectToHide : Renderer;
function Start()
{
ObjectToHide.enabled = false;
}
For question 2:
var HideTags : GameObject;
function Start()
{
var HideTags = GameObject.FindWithTag ("--tag--");
HideTags.active = false;
}
I believe.
For question 3, you will need to find some kind of script that would do that, unfortunately I don't know how to code for that ... wait for more responses.
---- EDIT ----
This will allow your object to turn on after 3 seconds
var ObjectToHide : Renderer;
var Timer : float = 3;
function Start()
{
ObjectToHide.enabled = false;
Invoke("LightsOn", Timer);
}
function LightsOn()
{
ObjectToHide.enabled = true;
}