after implementing the fix recomendedby Guidanel i now have this error error CS0019: Operator +=' cannot be applied to operands of type UnityEngine.Quaternion’ and `int’ at lines 55 and 61 of this script

   using UnityEngine;
using System.Collections;

public class movecamera : MonoBehaviour {

	public int edgeboundry = 10;
	public int minheight;
	public int maxheight;
	bool minheightreached;
	bool maxheightreached;
	public int rotspeed;
	
	void Awake ()
	{
		minheightreached = false;
		maxheightreached = false;
	}
	
	void Update ()
	{
		
		
		
		
		
		minheightreached = transform.position.y <= minheight;
		
		maxheightreached = transform.position.y >= maxheight;
		
		
		if (Input.GetAxis ("Vertical") < 0 * Time.deltaTime){            
			
			transform.position += new Vector3 (0, 0, -0.2f);
			
		}
		
		if (Input.GetAxis ("Vertical") > 0 * Time.deltaTime){             
			
			transform.position += new Vector3 (0, 0, 0.2f);
		}
		
		if (Input.GetAxis ("Horizontal") < 0 * Time.deltaTime){ 
   
			transform.position += new Vector3 (-0.2f, 0, 0);
			
		}
		if (Input.GetAxis ("Horizontal") > 0 * Time.deltaTime){           

			transform.position += new Vector3 (0.2f, 0, 0);
			
		}
		
		if (Input.GetKey("q") || (Input.GetMouseButtonDown(2))){
		
			transform.rotation += rotspeed;
		
		}
		
		if (Input.GetKey("e") || (Input.GetMouseButtonDown(2))){      
			
			transform.rotation += -rotspeed;
			
		}
		
		
		if(Input.GetAxis("Ymovement") > 0.0f && (maxheightreached == false))
		{ 
			transform.position += new Vector3(0, 0.2f, 0);
		}
		
		if(Input.GetAxis("Ymovement") < 0.0f && (minheightreached == false))
		{
			transform.position += new Vector3(0, -0.2f, 0);
		}
		
		
	}
}

could someone advise me on what im doing wrong thanks in advance

You put too many parenthesis.

if (Input.GetKey("q")) || (Input.GetMouseButtonDown("2"))

should be

if (Input.GetKey("q") || Input.GetMouseButtonDown("2"))

same for the following if statement.