Animation blending/crossfading sword help

 #pragma strict
 var swordSpeed = 0.5;
 var slash: AudioClip[];
 private var t:float;
 var head:CharacterController;
 
 function Start(){SwordBobble();}
 
 function SwordBobble(){
     var sword = gameObject.Find("blade");
     var ani = sword.animation;
     while(true){
         if(head.isGrounded  && head.velocity.magnitude >= 4){ //&& !animation.animations.swordslash.isPlaying){
             ani["SwordBobble"].speed = 1;
             ani.Play("SwordBobble");
             //ani.CrossFade("SwordBobble");            
             yield WaitForSeconds(0.001);
         }
         else{
             ani["SwordBobble"].speed = 0;
             //animation.Stop();
             yield;
         }
     }
 }
 
 function Update(){
     if(GameObject.Find("Gameover") == null){Disable();}
     t += Time.deltaTime;
     if(t >= 0.5 && GameObject.Find("Enabled") == null && GameObject.Find("blade") != null && GameObject.Find("Gameover") != null && GameObject.Find("PauseNo")!= null && GameObject.Find("GUI_black").guiTexture.color.a <= 0){
         if(Input.GetButtonDown("Fire1")){
             var sword = gameObject.Find("blade");
              if(sword != null && GameObject.Find("SlashFalse") != null){
                  //var ani = sword.animation;
                  var anistate = sword.animation["swordslash"];
                      sword.animation.Play("swordslash");
                      audio.pitch = Random.Range(1.0 - 0.05, 1.0 + 0.05);
                      var ran = slash[Random.Range(0,slash.Length)];
                      audio.clip = ran;
                      audio.Play();
                          t = 0;
             }
         }
     }    
 }

I've been having a bit of trouble lately. As you can see, I have two main functions of this script: one triggers a SwordBobble, like where the sword bounces around while walking, and the second function is to trigger a sword slashing animation, which plays when triggered by Fire1.

My big problem is that while I am walking, the SwordBobble animation is playing, so when I try to play a sword slash animation, it's being overlapped by SwordBobble.

I don't know the difference between crossfade and blending exactly - is blending to literally mix in two or more animations and crossfade just "fades" out an animation? What would that look like? I'm confused on what they do.

So, my goal here is to make it so SwordSlash will, I guess "blend" in with SwordBobble, and then play the swordslash animation, and then once the swordslash animation is finished, it will automatically go back/blend back to SwordBobble mode.

Swordslash only plays when I am not moving, and I need it so it can play while moving as SwordBobble is playing also.

I don't know how I can set up these blending and crossfading functions, so may someone help me on how I can accomplish this? Please do not speak with a lot of elitism, as I usually can't follow what you're saying. Thank you very much for taking the time to read my frustration.