public bool HasAssociatedFeatureService {get;}

{
  featSceneLayer = MapView.Active.Map.GetLayersAsFlattenedList()
                     .OfType<FeatureSceneLayer>().FirstOrDefault();
  if (!featSceneLayer.HasAssociatedFeatureService ||
      !featSceneLayer.IsEditable)
  {
    //not supported - exit the function
  }
  //TODO continue editing here...
}

{
  //must support editing!
  if (!featSceneLayer.HasAssociatedFeatureService ||
      !featSceneLayer.IsEditable)
  {
    //not supported - exit the function
  }

  //Check geometry type...must be point in this example
  var editOp = new EditOperation()
  {
    Name = "Create new 3d point feature",
    SelectNewFeatures = true
  };

  var attributes = new Dictionary<string, object>();
  //mapPoint contains the new 3d point location
  attributes.Add("SHAPE", mapPoint);
  attributes.Add("TreeID", "1");
  editOp.Create(featSceneLayer, attributes);
  editOp.ExecuteAsync();
}

{
  if (!featSceneLayer.HasAssociatedFeatureService ||
    !featSceneLayer.IsEditable)
    return;
  // Note: call within QueuedTask.Run()
  {
    var delOp = new EditOperation()
    {
      Name = "Delete selected features"
    };
    //Assuming we have a selection on the layer...
    delOp.Delete(featSceneLayer, featSceneLayer.GetSelection().GetObjectIDs());
    delOp.ExecuteAsync();
  }
}

{
  //must support editing!
  if (!featSceneLayer.HasAssociatedFeatureService ||
      !featSceneLayer.IsEditable)
    return;

  // Note: call within QueuedTask.Run()
  {
    var editOp = new EditOperation()
    {
      Name = "Edit FeatureSceneLayer Attributes",
      SelectModifiedFeatures = true
    };
    //make an inspector
    var inspector = new Inspector();
    //get the attributes for the specified oid
    inspector.Load(featSceneLayer, oid);
    inspector["PermitNotes"] = "test";//modify
    editOp.Modify(inspector);
    editOp.Execute();//synchronous flavor
  }
}

{
  // Note: call within QueuedTask.Run()
  {
    if (featSceneLayer.HasAssociatedFeatureService)
    {
      using (var fc = featSceneLayer.GetFeatureClass())
      {
        //TODO query underlying feature class
      }
    }
  }
}

{
  //assume the geometry used in SelectFeaturesEx() is coming from a 
  //map tool...
  //SketchType = SketchGeometryType.Rectangle;
  //SketchOutputMode = SketchOutputMode.Screen;

  // Note: call within QueuedTask.Run()
  {
    var result = MapView.Active.SelectFeaturesEx(geometry);
    //Get scene layers with selections
    var scene_layers = result.ToDictionary<FeatureSceneLayer>();
    foreach (var kvp in scene_layers)
    {
      var scene_layer = kvp.Key as FeatureSceneLayer;
      var sel_oids = kvp.Value;
      //If there are attributes then get them
      if (scene_layer.HasAssociatedFeatureService)
      {
        var insp = new Inspector();
        foreach (var objectid in sel_oids)
        {
          insp.Load(scene_layer, objectid);
          //TODO something with retrieved attributes
        }
      }
    }
  }
}

{
  if (featSceneLayer.HasAssociatedFeatureService)
  {
    //Can Select and Search...possibly edit
  }
}

{
  if (!featSceneLayer.HasAssociatedFeatureService)
    return;//Search and Select not supported

  //Multipatch (Object3D) or point?
  //var is3dObject = ((ISceneLayerInfo)featSceneLayer).SceneServiceLayerType 
  //                                  == esriSceneServiceLayerType.Object3D;
  var is3dObject = featSceneLayer.FeatureSceneLayerType == FeatureSceneLayerType.Object3D;
  // Note: call within QueuedTask.Run()
  {
    var queryFilter = new QueryFilter
    {
      WhereClause = "Name = 'Ponderosa Pine'",
      SubFields = "*"
    };

    int rowCount = 0;
    //or select... var select = featSceneLayer.Select(queryFilter)
    using (RowCursor rowCursor = featSceneLayer.Search(queryFilter))
    {
      while (rowCursor.MoveNext())
      {
        using (var feature = rowCursor.Current as Feature)
        {
          oid = feature.GetObjectID();
          var shape = feature.GetShape();
          var attrib = feature["Name"];
          if (is3dObject)
          {
            //shape is a multipatch
          }
          else
          {
            //shape is a point
          }
          rowCount += 1;
        }
      }
    }
  }
}

{
  if (featSceneLayer.HasAssociatedFeatureService)
    return;//Search and Select not supported

  // Note: call within QueuedTask.Run()
  {
    QueryFilter qf = new QueryFilter()
    {
      ObjectIDs = new List<long>() { 6069, 6070, 6071 },
      SubFields = "*"
    };
    featSceneLayer.Select(qf, SelectionCombinationMethod.New);

    featSceneLayer.HideSelectedFeatures();
    var selectionCount = featSceneLayer.SelectionCount;

    featSceneLayer.ShowHiddenFeatures();
    selectionCount = featSceneLayer.SelectionCount;
  }
}

// Note: call within QueuedTask.Run()
{
  if (!featSceneLayer.HasAssociatedFeatureService)
    return;//no search or select

  //Select all features within the current map view
  var sz = MapView.Active.GetViewSize();
  var map_pt1 = MapView.Active.ClientToMap(new System.Windows.Point(0, sz.Height));
  var map_pt2 = MapView.Active.ClientToMap(new System.Windows.Point(sz.Width, 0));

  //Convert to an envelope
  var temp_env = EnvelopeBuilderEx.CreateEnvelope(map_pt1, map_pt2, MapView.Active.Map.SpatialReference);

  //Project if needed to the layer spatial ref
  SpatialReference sr = null;
  using (var fc = featSceneLayer.GetFeatureClass())
  using (var fdef = fc.GetDefinition())
    sr = fdef.GetSpatialReference();

  var env = GeometryEngine.Instance.Project(temp_env, sr) as Envelope;

  //Set up a query filter
  var sf = new SpatialQueryFilter()
  {
    FilterGeometry = env,
    SpatialRelationship = SpatialRelationship.Intersects,
    SubFields = "*"
  };

  //Select against the feature service
  var select = featSceneLayer.Select(sf);
  if (select.GetCount() > 0)
  {
    //enumerate over the selected features
    using (var rc = select.Search())
    {
      while (rc.MoveNext())
      {
        using (var feature = rc.Current as Feature)
        {
          oid = feature.GetObjectID();
          //etc.
        }
      }
    }
  }
  MapView.Active.Map.ClearSelection();
}