Sketchup-style camera movement/rotation?.

Hi there, I'm brand-new to Unity - and programming in general, but I'm beginning work on an RTS/RPG game. I've been using Sketchup for a long time, and I really like how the camera movement/rotation works within the program(middle click+drag to rotate, middle+left+drag to pan).

I haven't been able to find any leads on how to replicate that style in Unity , though. I think starting with a mouse position/control script to reference back to is the right way to go, but I'm not sure where to go from there, or if what I have will even work for both unit and camera control in the way that I'd like.

Here's what I have so far, based on Maroe's "DetectClicksAndTouches"(which was just left/right click detection and touch functionality) - with left/right/middle clicking, then shift+click for each, and middle+left hold-down:

 using UnityEngine;
 using System.Collections;
 
 public class DetectClicks : MonoBehaviour
 {    
     public Camera detectionCamera;
     
     //This variable adds a Debug.Log call to show what was touched
     public bool debug = false;
     
     //This is the actual camera we reference in the update loop, set in Start()
     private Camera _camera;
     
     void Start()
     {
         if(detectionCamera != null)
         {
             _camera = detectionCamera;
         }
         else
         {
             _camera = Camera.main;
         }
     }
     
     // Update is called once per frame
     void Update ()
     {
         Ray ray;
         RaycastHit hit;
             
 // LEFT CLICK
         
             //Check to see if we've left-clicked without shift or middle mouse button
             if(Input.GetMouseButtonDown(0) && (!Input.GetKey(KeyCode.LeftShift)) && (!Input.GetMouseButton(2)))  
             {
                 //Set up our ray from screen to scene
                 ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                 //If we hit...
                 if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                 {
                         Debug.Log("You left clicked " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                     
                     //Run the Clicked() function on the clicked object
                     hit.transform.gameObject.SendMessage("LeftClicked", hit.point, SendMessageOptions.DontRequireReceiver);
                         
                 
                 }
             
             }
         
                     //SHIFT-LEFT CLICK
                     else if(Input.GetMouseButtonDown(0) && (Input.GetKey(KeyCode.LeftShift)))
                     {
                         //Set up our ray from screen to scene
                         ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                         //If we hit...
                         if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                         {
                                 Debug.Log("You shift-left clicked " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                             //Run the Clicked() function on the clicked object
                             hit.transform.gameObject.SendMessage("ShiftLeftClicked", hit.point, SendMessageOptions.DontRequireReceiver);
                         }
                     }
         
         
             
 // RIGHT CLICK
             
             //Check to see if we've right-clicked without shift
             if(Input.GetMouseButtonDown(1) && (!Input.GetKey(KeyCode.LeftShift)))  
             {
                 //Set up our ray from screen to scene
                 ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                 //If we hit...
                 if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                 {
                         Debug.Log("You right clicked " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                     
                     //Run the Clicked() function on the clicked object
                     hit.transform.gameObject.SendMessage("RightClicked", hit.point, SendMessageOptions.DontRequireReceiver);
             
                 }            
             }
         
 
             
 // MIDDLE CLICK (HOLD DOWN (camera movement?))
             
             //Check to see if we've middle-clicked and are holding down without shift or left mouse button
             if(Input.GetMouseButton(2) && (!Input.GetKey(KeyCode.LeftShift) && (!Input.GetMouseButton(0))))
             {
                 //Set up our ray from screen to scene
                 ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                 //If we hit...
                 if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                 {
                         Debug.Log("You are middle-cicking " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                     
                     //Run the Clicked() function on the clicked object
                     hit.transform.gameObject.SendMessage("MiddleClicked", hit.point, SendMessageOptions.DontRequireReceiver);
                 
 
                 }
             }
         
     //SHIFT-MIDDLE CLICK
                     else if(Input.GetMouseButton(2) && (Input.GetKey(KeyCode.LeftShift)))
                     {
                         //Set up our ray from screen to scene
                         ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                         //If we hit...
                         if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                         {
                                 Debug.Log("You are shift-middle clicking " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                             //Run the Clicked() function on the clicked object
                             hit.transform.gameObject.SendMessage("ShiftMiddleClicked", hit.point, SendMessageOptions.DontRequireReceiver);
                         }
                     }
         
     //LEFT-MIDDLE CLICK
                     else if(Input.GetMouseButton(2) && (Input.GetMouseButton(0)))
                     {
                         //Set up our ray from screen to scene
                         ray = _camera.ScreenPointToRay(Input.mousePosition); 
                 
                         //If we hit...
                         if(Physics.Raycast (ray, out hit, Mathf.Infinity))
                         {
                                 Debug.Log("You are left-middle clicking " + hit.collider.gameObject.name,hit.collider.gameObject);
                     
                             //Run the Clicked() function on the clicked object
                             hit.transform.gameObject.SendMessage("LeftMiddleClicked", hit.point, SendMessageOptions.DontRequireReceiver);
                         }
                     }
             
             
             
         }
     }

Would this work for all mouse controls in the game(camera/units/etc)? Which direction should I head from here if I want to get camera movement down first?

Thank you, and sorry for the long post.