Can Editor Windows function like the inspector ?

I think you have the Editor Windows a bit confused with components. Each game object has a component on it. When you select a game object it shows each of the components on the game object, like the rigidbody.

Editor Windows are not run at runtime if you try to use any actual Editor Window. What you want is to create a script. When you create a script in Unity it will act like a component. This way you can drag the script onto your game object and it will be like a component. Any public variables in the script will shown in the inspector and you can change them for each object, just like the mass value on the rigidbody.

Here is an example script:

 using UnityEngine;
 using System.Collections;
 
 public class ScaleScript : MonoBehaviour {
 
     //since this is public it will show in the inspector. 
     //even though it is set to 1 here if we change it in the
     //inspector it will stay as the value we changed it to.
     public float scale = 1.0f;
 
     // Use this for initialization
     void Start () {
         //multiplies the current scale by the SCALE variable. 
         gameObject.transform.localScale = gameObject.transform.localScale * scale;
     }
     
     // Update is called once per frame
     void Update () {
     
     }
 }
 

Here is what it looks like in the inspector. I've put it on each sphere and set the scale to a different value. When we run the scene it changes each one to the value we had set it to. This is like the mass we would set for the rigidbody.

Now there are Editors that you can make to make the script look nicer and fancier and editor windows that are not attached to any object, but for either to work with a game object you need to have a script coded and put on it first like above. I do apologize if this is not what you are looking for. You question was a bit hard to read and understand. Please leave a comment if you need clarification or a different answer.