Cleaning Up Vector (array like) in pure AS3 project

Question

I have been learning a game type animation from a tutorial at this site: http://www.emanueleferonato.com/2011/11/08/as3-version-of-nodes-engine-full-playable-game- with-infinite-solvable-levels/. Source code there online and also available for download.
Want to try to set up additional levels of difficulty, involving adding more draggables and targets. In order to change this level during a game, (with a set of radio buttons and change handler noting the change in radio button selection) using a pure AS3 and single frame necessitates removing (cleaning up) the draggables and targets already placed on stage in 2 Vector type arrays.
Have tried various versions of removeChild, removeChildAt with no success.
Here is the relevant AS3. Maybe someone could suggest a way to clean up/remove all Vector members before the new ones are instantiated on stage. If not removed, they end up at 0,0, one atop the other, while the new ones are randomly placed onto the stage.
Thank you for your help.
public class Main extends Sprite {
        private const DRAGGABLES:Number=4;
        private const TARGETS:Number=5;
        private var draggableNode:DraggableNode;
        private var target:Target;
        private var laserCanvas:Sprite=new Sprite();
        private var draggableVector:Vector.<DraggableNode>=new Vector.<DraggableNode>();
        private var targetVector:Vector.<Target>=new Vector.<Target>();
        private var isDragging:Boolean=false;
        public function Main() {
            addChild(laserCanvas);
            placeDraggables(false);
            placeTargets(false);
            shuffleDraggables();
            drawLaser();
            stage.addEventListener(MouseEvent.MOUSE_MOVE,moving);
private function placeDraggables(justMove:Boolean):void {
            for (var i:Number=0; i<DRAGGABLES; i++) {
                if (! justMove) {
                    draggableNode=new DraggableNode();
                    addChild(draggableNode);
                    draggableVector.push(draggableNode);
                    draggableNode.addEventListener(MouseEvent.MOUSE_DOWN,drag);
                    draggableNode.addEventListener(MouseEvent.MOUSE_UP,dontDrag);
                do {
                    var wellPlaced:Boolean=true;
                    draggableVector[i].x=Math.floor(Math.random()*600)+20;
                    draggableVector[i].y=Math.floor(Math.random()*440)+20;
                    for (var j:Number=i-1; j>=0; j--) {
                        if (getDistance(draggableVector[j],draggableVector[i])<150) {
                            wellPlaced=false;
                } while (!wellPlaced);
        private function placeTargets(justMove:Boolean):void {
            for (var i:Number=0; i<TARGETS; i++) {
                if (! justMove) {
                    target=new Target();
                    addChildAt(target,0);
                    targetVector.push(target);
                    target.alpha=0.5;
                do {
                    var wellPlaced:Boolean=true;
                    var segment=Math.floor(Math.random()*DRAGGABLES);
                    var p1:Sprite=draggableVector[segment];
                    var p2:Sprite=draggableVector[(segment+1)%DRAGGABLES];
                    var angle:Number=Math.atan2((p2.y-p1.y),(p2.x-p1.x))
                    var targetDistance:Number=Math.random()*getDistance(p1,p2);
                    targetVector[i].x=p1.x+targetDistance*Math.cos(angle);
                    targetVector[i].y=p1.y+targetDistance*Math.sin(angle);
                    for (var j:Number=i-1; j>=0; j--) {
                        if (getDistance(targetVector[j],targetVector[i])<50) {
                            wellPlaced=false;
                    for (j=0; j<DRAGGABLES; j++) {
                        if (getDistance(draggableVector[j],targetVector[i])<50) {
                            wellPlaced=false;
                } while (!wellPlaced);

Answer 1

about coding, this is an excerpt from a book i wrote (Flash Game Development: In a Social, Mobile and 3D World),
it's taken from a chapter that shows how coding typically evolves for a novice with a main idea and then progresses as more and more features are added:
Everything works the way it should but there is a major problem. Actually, there is more than one major problem and there are some minor problems but I will address the biggest problem, first: my Main class is quickly becoming a mess.
I have all this code for controlling player in Main and I will need more code which will make Main an even bigger mess. In addition, I will need to add an introduction view (by view, I mean what is presented on-stage) to give some information about the game and I should probably allow users to customize the keys they use for movement. Not everyone likes using the arrow keys. (Heck, I do not like using the arrow keys.) In addition, I will need a game-over view, eventually.
I am heading for a major mess in Main. So, while I can continue to put all my coding in Main, that is just like putting all your code in frame 1 of the main timeline and that bypasses one of the biggest advantages of OOP, encapsulation.
By encapsulation, I mean each class should contain only the information it needs to do its job. I want my Main class to control which views are presented on-stage. When the game starts, Main will add an intro view. When the user is finished with the intro view, Main will remove the intro view and add the game view (where the player and enemy tanks will fight) and when the game is over, Main will remove the game view and add the game over view.
I will use an IntroView class to control what happens in the introduction view and I'll use a GameView class to monitor what happens when player and enemy fight and an EndView to control what is displayed when combat is over - maybe the user's score or a taunting message.
I do not think I want the GameView class to control the fighting. I want all the code that controls player to be in the PlayerTank class and all the code that controls enemy to be in the EnemyTank class. That will simplify Main so it is easier to work with, will provide better encapsulation and will make it easier and faster to find the code I need to edit when changes and additions are needed.
While I am simplifying my code, I am going to create a keyboard controls class (KBcontrols) to store the key codes for moving left, right, up and down. I'm going to use static methods so I can assign those key codes in IntroView and use them in PlayerTank.
I do not want to be forced to pass those key codes back-and-forth because I am going to have one PlayerTank instance in IntroView (so users can test the keyboard controls) and a different PlayerTank instance in GameView. In addition, I may later want to allow users to re-define the keyboard controls while in GameView or elsewhere. I could make KBcontrols a singleton class but I feel like making it a class with static properties for no special reason.
(Actually, I already used a singleton class in Chapter 4 for a shape-based hit test that I showed in the BitmapData section. So, showing the other way to make data easily available among several classes is reasonable.)
There are quite a few things I am thinking about adding (like scoring and a timer and enemy intelligence etc) and I do not know exactly what classes I'm going to have at the end of this project and I sure do not know all the code that will be in each class that I anticipate will be needed. That may be a little unsettling but it is how applications and games evolve (at least, when I am the developer).