FlashLight Fixes Please??

I have a working flashlight script that drains out the energy of my flashlight and turns it off, I want to fix some things, any suggestions will help a lot:):)

1) When the power of the flashlight goes out, i can still press f and hear the sound of the button to turn the flashlight on/of... How do i disable it until my flashlight has energy again??

2)I have another Script to pick up a flashlight object that i made by going through the object, the script goes attached to the player and the object must have a "FlashLight" tag. I would like that when i pick up this item, just then the first script gets activated, so then i can press "f" to turn the flashlight on and start draining it's batteries

3)I would prefer to pick the flashlight up by pressing "e" near it...:)

Thats all, If anyone can help me in any of the 3 problems it will mean a lot:)

The FlashlightPickUp Script(attached to the player):

 private var hit : RaycastHit;
 private var rayDistance : float;
 private var contactPoint : Vector3;
 var PickupSound: AudioClip;
     
 function OnTriggerEnter (other : Collider) {     
     if (other.CompareTag ("Flashlight")) { 
        audio.PlayOneShot(PickupSound);    
        Destroy(other.gameObject);               
     } 
 }

The FlashLight Script, wich drains energy and can be turned on/off with "f" key:

 var lightSource : Light; //Connect the light source in the Inspector
 var shootSound:AudioClip;
 static var energy : float = 100; //The energy amount of the flashlight
 static var turnedOn : boolean = false; //Boolean to check whether it's turned on or off
 private var drainSpeed : float = 9.0; //The speed that the energy is drained
  lightSource.enabled = false; 
 function Update () {
     if (Input.GetKeyDown(KeyCode.F)) ToggleFlashlight();
         
 }
  
 //When the player press F we toggle the flashlight on and off
 function ToggleFlashlight () {
     turnedOn=!turnedOn;
       audio.PlayOneShot(shootSound);
     if (turnedOn && energy>0) {
        TurnOnAndDrainEnergy();
     } else {
        lightSource.enabled = false;
      
     }
 }
  
 //When the flashlight is turned on we enter a while loop which drains the energy
 function TurnOnAndDrainEnergy () {
     lightSource.enabled = true;
     while (turnedOn && energy>0) {
        energy -= drainSpeed*Time.deltaTime;
        yield;
     }
     lightSource.enabled = false;
 //I tried here with----->   shootSound.enable = false;     ,it didn't work
 }
  
 //This is called from outside the script to alter the amount of energy
 static function AlterEnergy (amount : int) {
     energy = Mathf.Clamp(energy+amount, 0, 100);
 }