randomly Instantiate items

I'm trying to Instantiate multiple enemy spawn points at random locations when my level loads, making sure they don't overlap within a certain radius, of each other, main character, and a boss area. everything is almost working great but from what i can tell nothing is being spawned to the right or down from any of the other already placed objects. its also taking 30sec to 1 min to calculate the 20 spawn points... If anyone can help with this issue it would be greatly appreciated. I'm also attacking a screenshot of whats happening. the white dots are placeholders for the enemy spawnpoints.

Varriable to check if valid position:

     static public bool CheckIfInSquare(Vector3 NewObjectPosition, Vector3 OldObjectsPosition, float RadiusBetweenObjects){
         if (NewObjectPosition.x < OldObjectsPosition.x - RadiusBetweenObjects || NewObjectPosition.x > OldObjectsPosition.x + RadiusBetweenObjects
             && NewObjectPosition.z < OldObjectsPosition.z - RadiusBetweenObjects || NewObjectPosition.z > OldObjectsPosition.z + RadiusBetweenObjects){
             return true;
         } else{
             return false;
         }
     }

Level Script

 // Public
 public GameObject BossArea01;
 public GameObject SpawnPointMarker01;
 // Private
 private Vector3 BossArea01Position;
 private GameObject Spawnpoint01;
 private GameObject Spawnpoint02;
 private GameObject Spawnpoint03;
 private GameObject Spawnpoint04;
 private GameObject Spawnpoint05;
 private GameObject Spawnpoint06;
 private GameObject Spawnpoint07;
 private GameObject Spawnpoint08;
 private GameObject Spawnpoint09;
 private GameObject Spawnpoint10;
 private GameObject Spawnpoint11;
 private GameObject Spawnpoint12;
 private GameObject Spawnpoint13;
 private GameObject Spawnpoint14;
 private GameObject Spawnpoint15;
 private GameObject Spawnpoint16;
 private GameObject Spawnpoint17;
 private GameObject Spawnpoint18;
 private GameObject Spawnpoint19;
 private GameObject Spawnpoint20;
 private int SummonSpawnPointInt = 1;
 // ********************************   Start   *****************************************
 void Start () {
     // Randomly Select Boss Area Position
     int rand = Random.Range (1, 5);
     if (rand == 1){
         BossArea01Position = new Vector3 (150, .02f, 150);
     } else if (rand == 2){
         BossArea01Position = new Vector3 (-150, .02f, -150);
     } else if (rand == 3){
         BossArea01Position = new Vector3 (150, .02f, -150);
     } else if (rand == 4){
         BossArea01Position = new Vector3 (-150, .02f, 150);
     }
     // Summon Boss Area
     Instantiate (BossArea01, BossArea01Position, Quaternion.identity);
 }
 // *******************************   Update   *****************************************
 void Update () {
     // Randomly Summon SpawnPointMarker
     if (SummonSpawnPointInt <= 20){
         Vector3 position = new Vector3 (Random.Range (-175, 175), 1, Random.Range (-175, 175));
         if (Galatia420.CheckIfInSquare (position, Character01Movement.MainCharacterPosition, 20)){//20
             if (Galatia420.CheckIfInSquare (position, BossArea01Position, 35)){//35
                 if (Spawnpoint01 == null || Galatia420.CheckIfInSquare (position, Spawnpoint01.transform.position, 10))//20
                 if (Spawnpoint02 == null || Galatia420.CheckIfInSquare (position, Spawnpoint02.transform.position, 10))
                 if (Spawnpoint03 == null || Galatia420.CheckIfInSquare (position, Spawnpoint03.transform.position, 10))
                 if (Spawnpoint04 == null || Galatia420.CheckIfInSquare (position, Spawnpoint04.transform.position, 10))
                 if (Spawnpoint05 == null || Galatia420.CheckIfInSquare (position, Spawnpoint05.transform.position, 10))
                 if (Spawnpoint06 == null || Galatia420.CheckIfInSquare (position, Spawnpoint06.transform.position, 10))
                 if (Spawnpoint07 == null || Galatia420.CheckIfInSquare (position, Spawnpoint07.transform.position, 10))
                 if (Spawnpoint08 == null || Galatia420.CheckIfInSquare (position, Spawnpoint08.transform.position, 10))
                 if (Spawnpoint09 == null || Galatia420.CheckIfInSquare (position, Spawnpoint09.transform.position, 10))
                 if (Spawnpoint10 == null || Galatia420.CheckIfInSquare (position, Spawnpoint10.transform.position, 10))
                 if (Spawnpoint11 == null || Galatia420.CheckIfInSquare (position, Spawnpoint11.transform.position, 10))
                 if (Spawnpoint12 == null || Galatia420.CheckIfInSquare (position, Spawnpoint12.transform.position, 10))
                 if (Spawnpoint13 == null || Galatia420.CheckIfInSquare (position, Spawnpoint13.transform.position, 10))
                 if (Spawnpoint14 == null || Galatia420.CheckIfInSquare (position, Spawnpoint14.transform.position, 10))
                 if (Spawnpoint15 == null || Galatia420.CheckIfInSquare (position, Spawnpoint15.transform.position, 10))
                 if (Spawnpoint16 == null || Galatia420.CheckIfInSquare (position, Spawnpoint16.transform.position, 10))
                 if (Spawnpoint17 == null || Galatia420.CheckIfInSquare (position, Spawnpoint17.transform.position, 10))
                 if (Spawnpoint18 == null || Galatia420.CheckIfInSquare (position, Spawnpoint18.transform.position, 10))
                 if (Spawnpoint19 == null || Galatia420.CheckIfInSquare (position, Spawnpoint19.transform.position, 10))
                 if (Spawnpoint20 == null || Galatia420.CheckIfInSquare (position, Spawnpoint20.transform.position, 10))
                     // Summon
                     switch (SummonSpawnPointInt){
                     case 1:
                         Spawnpoint01 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 2:
                         Spawnpoint02 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 3:
                         Spawnpoint03 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 4:
                         Spawnpoint04 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 5:
                         Spawnpoint05 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 6:
                         Spawnpoint06 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 7:
                         Spawnpoint07 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 8:
                         Spawnpoint08 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 9:
                         Spawnpoint09 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 10:
                         Spawnpoint10 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 11:
                         Spawnpoint11 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 12:
                         Spawnpoint12 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 13:
                         Spawnpoint13 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 14:
                         Spawnpoint14 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 15:
                         Spawnpoint15 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                 
                         break;
                     case 16:
                         Spawnpoint16 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 17:
                         Spawnpoint17 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 18:
                         Spawnpoint18 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 19:
                         Spawnpoint19 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         break;
                     case 20:
                         Spawnpoint20 = Instantiate (SpawnPointMarker01, position, Quaternion.identity);
                         SummonSpawnPointInt += 1;
                         Debug.Log ("Level01: Done Summoning Spawnpoints");
                         break;
                     }
             }
         }
     }
 }

p.s. if anyone has a good suggestion on how to shorten this... lol i'm up for suggestions ;) .