Moving multiple controllers at once

[Lupp_]

No PC? Are you in hell?

No seriously though, sorry, but that didn't help. When I try to do something new I want to do it properly so it looks nice, is useful and that I learn as much as possible.

This is what I want to achieve:

1. I want the script to run only when I have 2 or more splinecontrollers selected. I've been trying figure out how to get an int from Selection.stuff.., but no luck. I can't figure out how to check how many of the selected objects have the correct component. I don't even know if it is the correct approach, is there a way do a check if you are editing multiple items of the correct type (component)?
   
2. Once 1 is fixed I want, if it's even possible, to override how splinecontrollers move multiple objects now. I want, when you move the position slider during multi selection, to offset each controller by input value from the slider, instead of moving all to the same spot.
   
3. If 2 is not possible, I want a new slider to appear under the position slider that does point 2. Or if you can't modify other scripts at all I want the slider to appear next to the Curvy icons in the scene view.
   
4. When all this is done I need a check so all controllers stop moving when one hits the end of spline so the offsets doesn't get messed up, but this will probably be easy.
   

Right now I don't even know if I have setup the script correctly, so right now I'll appreciate all help.

Code:

using UnityEngine;
using UnityEditor;
using FluffyUnderware.Curvy.Controllers;

namespace FluffyUnderware.CurvyEditor.Controllers
{
   public class MoveMultipleControllers : EditorWindow
        {
       public void OnSelectionChange()
       {
           


       }
   }
}