BLOOD, BREATH & SWEAT & swears F%*$#$@!*;^%!!!!!

This would take a little while to provide code so I will only give you some headlines.

As stated in comments, you are heading into hours of headache if you do not know much about programming.

Your footsteps could be done using the animation event

http://docs.unity3d.com/Documentation/Components/animeditor-AnimationEvents.html.

Since you are a game artist, I reckon you are familiar with animation.

All you need to do is add a function when the foot animation curve is at the lowest(touching ground). Then you create a footstep texture that you apply flat on the ground at the foot position. Same for the bloody one, you just swap the material. You can use the Destroy function to remove your footsteps as the function has a timer in seconds.

The function below shows the principle with the mouse position, you just need to change for the foot position. Click left button to apply a "step", wait for 5 seconds and pooof...it is gone.

 var step:GameObject;
 var bloodyStep:GameObject;
 var ok:boolean = true;
 
 function Update(){
     if(Input.GetKeyDown(KeyCode.Space))ok=!ok;
     if(Input.GetMouseButtonDown(0)){
         var ray : RaycastHit;
                 if (Physics.Raycast (Camera.main.ScreenPointToRay (Input.mousePosition),ray)) {
                     if(ok){
                         var steps=Instantiate (step, ray.point, Quaternion.identity);
                         Destroy(steps,5.0f);
                     }else{
                         var blSteps=Instantiate (bloodyStep, ray.point, Quaternion.identity);
                         Destroy(blSteps,5.0f);
                     }
                 }
         }
 }

link text

You can try a very simplified version with the link at the bottom. Press space to swap colors.

For the breath, you use particle emitter that is position on the front of the mouth.

http://docs.unity3d.com/Documentation/Components/class-EllipsoidParticleEmitter.html

Unity has two particle system, legacy and shuriken. I would recommend legacy to start with. Shuriken has so many parameters that would get you lost.

I would tell you to start and look for all those and when you hit an issue come back here.

fafase has good advise.

You might also apply Decal textures for both footprints and blood. If you use a parallax shader with height you can get a pretty nice 'impression'

Thank you! thank you Fattle and Dave. And thank you for considering my "right brain" visual thinking mind. I think that I can do this and I appreciate the advice very much. Well, here we go...

I'd use a particle system that collides with your ground and uses gravity.