Hovercraft Non Working (Stability)

So I posted this question before but I have a different one now. I want to make a hovercraft in game and I found this guy's script here: (http://virtualrealitydesign4.blogspot.com/2012/01/script-for-hovercraft-mechanics.html)

which has 2 video parts here: (http://www.youtube.com/watch?feature=player_embedded&v=IYpwvtc0Fk8)

and here (http://www.youtube.com/watch?feature=player_embedded&v=ssZ0BE7s9zA).

I want to achieve that effect exactly however I can't seem to get his script to work in C#. I used a converter here: (http://files.m2h.nl//js_to_c.php) or even in Javascript.

Can anyone help me with this like how to set up my models and parenting and explaining how this works because I'm not too good at this and the creator seems to not be active anymore.

@hijinxbassist I appreciate the answer and yes I did that and got it to work however not perfectly. Because I only worked with Javascript and C# since march, I'm not good at it.

@syclamoth Thanks a million! Here is the code I converted and got it to work however with a flaw. The 5 Spheres that takes care of stability are not at the four corners but in the center stuck together which messes up my collision stuff.

Here is the converted code:

 using UnityEngine;
 using System.Collections;
 
 public class ScifiHover : MonoBehaviour
 {
     public float forwardPower = 75000.0f;
     public float steerPower = 100000.0f;
     public float landingPower = 15.0f;
     public float jumpingPower = 15.0f;
     public float hoverHeight = 15.0f;
     public float stability = 2;
     public GameObject body;
     public float speedUpdate;
     private Vector3[] hitNormal = new Vector3[5];
     private Quaternion rotation;
     private float increment;
     private Vector3[] lastNormals = new Vector3[5];
     private bool physicsSetup = false;
     private Vector3 boxDim;
     private Vector3[] cornersPoint = new Vector3[5];
     private Transform[] corners = new Transform[5];
     private BoxCollider boxCollider;
     private float yBounce;
     private Vector3 lastPosition;
     private float distance;
     private Vector3 average;
 
     void Awake()
     {
         InitializePhysics();
     }
 
     void Update()
     {
         CalculateSpeed();
     }
 
     void FixedUpdate()
     {
         if (physicsSetup)
         {
             RaycastHit hit;
 
             for (int i = 0; i <= corners.Length - 1; i++)
             {
                 if (Physics.Raycast(corners[i].position, -corners[i].up, out hit, (hoverHeight + 5)))
                 {
                     if (hit.collider.gameObject.tag == "Floor")
                     {
                         hitNormal[i] = body.transform.InverseTransformDirection(hit.normal);
                         if (lastNormals[i] != hitNormal[i])
                         {
                             increment = 0;
                             lastNormals[i] = hitNormal[i];
                         }
                         distance = hit.distance;
                         if (hit.distance < hoverHeight)
                         {
                             constantForce.relativeForce = (-average + transform.up) * rigidbody.mass * jumpingPower * rigidbody.drag * Mathf.Min(hoverHeight, hoverHeight / distance);
                         }
                         else
                         {
                             constantForce.relativeForce = -(transform.up) * rigidbody.mass * landingPower * rigidbody.drag / Mathf.Min(hoverHeight, hoverHeight / distance);
                         }
                     }
                 }
             }
             average = -(hitNormal[0] + hitNormal[1] + hitNormal[2] + hitNormal[3] + hitNormal[4]) / 2;
 
             if (increment != 1) { increment += 0.03f; }
 
             rotation = Quaternion.Slerp(body.transform.localRotation, Quaternion.Euler(average * Mathf.Rad2Deg), increment);
             Quaternion temp = rotation;
 
             temp.y = transform.up.y * Mathf.Deg2Rad;
             body.transform.localRotation = temp;
 
             float fwdForce = Input.GetAxis("Vertical") * forwardPower;
             rigidbody.AddForce(transform.forward * fwdForce);
 
             float steerForce = Input.GetAxis("Horizontal") * steerPower;
             rigidbody.AddTorque(transform.up * steerForce);
         }
     }
 
     void OnDrawGizmos()
     {
         if (corners[0] != null) { Gizmos.DrawWireSphere(corners[0].position, 5); }
         if (corners[1] != null) { Gizmos.DrawWireSphere(corners[1].position, 5); }
         if (corners[2] != null) { Gizmos.DrawWireSphere(corners[2].position, 5); }
         if (corners[3] != null) { Gizmos.DrawWireSphere(corners[3].position, 5); }
         if (corners[4] != null) { Gizmos.DrawWireSphere(corners[4].position, 5); }
     }
 
     void CalculateSpeed()
     {
         if (lastPosition != transform.position)
         {
             float distance = Vector3.Distance(transform.position, lastPosition);
             speedUpdate = (distance / 1000) / (Time.deltaTime / 3600); //Km/h
         }
     }
 
     void InitializePhysics()
     {
         //This function will add a temporary box collider and get the corner positions
         boxCollider = body.AddComponent<BoxCollider>();
         boxDim = new Vector3(boxCollider.size.x * body.transform.localScale.x, boxCollider.size.y * body.transform.localScale.y, boxCollider.size.z * body.transform.localScale.z * stability);
         cornersPoint[0] = new Vector3(transform.position.x - boxDim.x / 2, transform.position.y - boxDim.y / 2, transform.position.z + boxDim.z / 2);
 
         cornersPoint[1] = new Vector3(boxDim.x / 2 + transform.position.x, transform.position.y - boxDim.y / 2, transform.position.z + boxDim.z / 2);
         cornersPoint[2] = new Vector3(boxDim.x / 2 + transform.position.x, transform.position.y - boxDim.y / 2, transform.position.z - boxDim.z / 2);
         cornersPoint[3] = new Vector3(transform.position.x - boxDim.x / 2, transform.position.y - boxDim.y / 2, transform.position.z - boxDim.z / 2);
         cornersPoint[4] = transform.position;
         Destroy(boxCollider);
 
         for (int i = 0; i <= cornersPoint.Length - 1; i++)
         {
             GameObject stablePlatform = GameObject.CreatePrimitive(PrimitiveType.Sphere);
             stablePlatform.name = "StablePlatform" + "(" + i + ")";
             stablePlatform.transform.parent = body.transform;
             stablePlatform.transform.localPosition = transform.InverseTransformPoint(cornersPoint[i]);
             corners[i] = stablePlatform.transform;
             Destroy(stablePlatform.GetComponent<MeshRenderer>());
             Destroy(stablePlatform.GetComponent<Collider>());
         }
         cornersPoint = null;
         physicsSetup = true;
     }
 }