Best Practices for something like this

Working on a project, after learning about "Garbage Collecting" and a couple other things from this forum (Thank you all) I was just wondering if someone could look over this bit of code and tell me if Im using best practices or if it is just sloppy as hell and im going about it all wrong.

ALSO, I understand to remove eventListeners and children added to the stage dynamically. But do you need to remove things such as Tweens, and Timers..

If I instantiate something using identifer = new something ();  Do I always need to remove this no matter what it is to keep everything clean?

package {

  import flash.display.MovieClip;
  import flash.utils.Timer;
  import flash.events.*;
  import fl.transitions.Tween;
  import fl.transitions.easing.Elastic;
  import fl.transitions.easing.Back;
  import fl.transitions.TweenEvent;

  public class ShooterProtoMAIN extends MovieClip {
  //MAIN MENU ASSETS
  public var MainMenu:mcMainMenu;
  public var MenuCredits:mcCredits;
  public var StartGameBttn:bttnStartGame;
  public var MainMenuTitle:mcTitle;
  public var MainMenuTitleTween:Tween;
  public var MenuCreditsTween:Tween;
  public var StartGameBttnTween:Tween;
  //PLAYER ASSETS
  public var Player:mcPlayer;
  public var PlayerReticle:mcReticle;
  public var ReadyCheck:mcReadyCheck;
  public var PlayerBase:mcBase;
  public var PreRoundTimer:Timer;
  public var PlayerControlEnabled:Boolean = false;
  public const PlayerMoveSpeed:Number = 3;

  public function ShooterProtoMAIN () {
  // constructor code
  }

  //MAIN MENU BEFORE GAME BEGINS
  private function MainMenuScreen () {
  //BUILD OUR MENU SCREEN
  MainMenu = new mcMainMenu ();
  stage.addChild (MainMenu);
  MainMenu.x = stage.stageWidth / 2;
  MainMenu.y = stage.stageHeight / 2;
  MainMenuTitle = new mcTitle ();
  stage.addChild (MainMenuTitle);
  MainMenuTitle.x = stage.stageWidth / 2;
  MainMenuTitleTween = new Tween(MainMenuTitle,"y",Elastic.easeOut,-50,100,1,true);
  MenuCredits = new mcCredits ();
  stage.addChild (MenuCredits);
  MenuCredits.x = stage.stageWidth / 2;
  MenuCreditsTween = new Tween(MenuCredits,"y",Elastic.easeOut,850,750,1,true);
  StartGameBttn = new bttnStartGame();
  stage.addChild (StartGameBttn);
  StartGameBttn.y = stage.stageHeight / 2;
  StartGameBttnTween = new Tween(StartGameBttn,"x",Elastic.easeOut,-50,stage.stageWidth / 2,1,true);
  StartGameBttn.addEventListener (MouseEvent.CLICK, StartTheShow);
  }

  private function StartTheShow (event:MouseEvent):void {
  MainMenuTitleTween = new Tween(MainMenuTitle,"y",Back.easeIn,100,-50,1,true);
  MenuCreditsTween = new Tween(MenuCredits,"y",Back.easeIn,750,850,1,true);
  StartGameBttnTween = new Tween(StartGameBttn,"x",Back.easeIn,stage.stageWidth / 2,-150,1,true);
  StartGameBttnTween.addEventListener (TweenEvent.MOTION_FINISH, MainMenuTweenFinished);
  }

  private function MainMenuTweenFinished (event:TweenEvent):void {
  MainMenuRinse ();
  BeginGame ();
  }

  //CLEANER FUNCTION FOR MAIN MENU;
  private function MainMenuRinse () {
  stage.removeChild (MainMenu);
  MainMenu = null;
  stage.removeChild (MenuCredits);
  MenuCredits = null;
  StartGameBttn.removeEventListener (MouseEvent.CLICK, StartTheShow);
  StartGameBttnTween.removeEventListener (TweenEvent.MOTION_FINISH, MainMenuTweenFinished);
  stage.removeChild (StartGameBttn);
  StartGameBttn = null;
  }