Keeping speed while crouching in midair and remove clipping while returning to standing

I've been working on making a good crouching script now for a while but no matter how I try I can't put the last pieces together.

One thing I want is that if you jump while running (standing) and then start to crouch in midair you should not slow down except for when landing on the ground. I've been trying some IsGrounded-functions but when I do the script just ignore the slowdown altogether and makes the player move around with normal standingspeed while crouching.

The other (and most important - I even dare to say gamebreaking) missing component is the fact that the player should not be able to stand up if standing up will result in the player clipping through objects. At the moment I can stand up straight from crouching anywhere which isn't how it normally works in games. I've tried to create a collider with the same size as the First Person Controller collider and used some collider scripts to make the game realize that while anything is touching this collider the player should not be able to stand.

The code so far looks like this (it's a modified version of a crouching script I found here a while ago):

var forWalkSpeed: float = 7; // regular speed forward var sideWalkSpeed: float = 7; // regular speed sidestep var backWalkSpeed: float = 7; // regular speed backward var forCrchSpeed: float = 3; // crouching speed forward var sideCrchSpeed: float = 3; // crouching speed sidestep var backCrchSpeed: float = 3; // crouching speed backward

internal var forSpeed: float; // the current speed state internal var sideSpeed: float; internal var backSpeed: float;

internal var crouchHeight : float; // variables for character height while crouching internal var crouchingHeight : float;
internal var standingHeight: float; // height of character while standing internal var crouching = false; // boolean is crouching? //internal var running = false; // boolean is running?

internal var characterMotor: CharacterMotor; //direct variable to the characterMotor internal var mainCamera: GameObject; // direct variable to the mainCamera

//var distToGround: float;

function Start() { //initialize characterMotor = GetComponent(CharacterMotor); mainCamera = gameObject.FindWithTag ("MainCamera"); standingHeight = mainCamera.transform.localPosition.y; crouchingHeight = (standingHeight - 0.9); crouchHeight = (standingHeight - crouchingHeight); distToGround = collider.bounds.extents.y; // get the distance to ground }

function Update() { //simple machine for setting the current speed of the character if(crouching) { forSpeed = forCrchSpeed; // slow down when crouching sideSpeed = sideCrchSpeed; backSpeed = backCrchSpeed; } //else if( running ) //{ // speed = runSpeed; //} else { forSpeed = forWalkSpeed; backSpeed = backWalkSpeed; sideSpeed = sideWalkSpeed; } /* //If the sprint button is clicked, and not crouching .. SPRINT!

 if (Input.GetKey("left ctrl") || Input.GetKey("right ctrl")){
     if(!crouching){
         running = true;
         //cameraZoom.sprint = true;  //sets sprint true so the camera knows to pan out
     }
 } else {
     //cameraZoom.sprint = false;
     running = false;
 } */

 // if crouch button has been pressed, put FPS into crouch
 if (Input.GetButtonDown ("Crouch")){
     if(crouching){
         stopCrouching();
         return;
     }
     if(!crouching)
          crouch();
 }
 // crouch with smoothing
 if(crouching)
 {
     if(mainCamera.transform.localPosition.y > crouchingHeight){
         if(mainCamera.transform.localPosition.y - (crouchHeight*Time.deltaTime*4) < crouchingHeight){
             mainCamera.transform.localPosition.y = crouchingHeight;
         }
         else 
         {
             mainCamera.transform.localPosition.y -= crouchHeight*Time.deltaTime*4;
         }
     }
 }
 else 
 {
     if(mainCamera.transform.localPosition.y < standingHeight){
         if(mainCamera.transform.localPosition.y + (crouchHeight*Time.deltaTime*4) > standingHeight){
             mainCamera.transform.localPosition.y = standingHeight;
         }
         else
         {
             mainCamera.transform.localPosition.y += crouchHeight*Time.deltaTime*4;
         }
     }
 }
 //set the max speed in the char motor;
 characterMotor.movement.maxForwardSpeed = forSpeed; // set max forward speed
 characterMotor.movement.maxSidewaysSpeed = sideSpeed; // max sideway speed
 characterMotor.movement.maxBackwardsSpeed = backSpeed; //max backwards speed

}

// sets the size of the collider to crouch size

function crouch() { this.GetComponent(CharacterController).height -= crouchHeight; this.GetComponent(CharacterController).center -= Vector3(0,crouchHeight/2, 0); crouching = true; }

// resets the size of the collider to standing size
function stopCrouching() { crouching = false; this.GetComponent(CharacterController).height += crouchHeight; this.GetComponent(CharacterController).center += Vector3(0,crouchHeight/2, 0); }

/ function IsGrounded(): boolean { return Physics.Raycast(transform.position, -Vector3.up, distToGround + 0.1); }/