I was able to place successfully the RadBrowseEditor on the form. I would like to suggest removing all references from your project and adding them anew. All referenced assemblies should have the same version (for example 2012.2 726). In order to open the folder select dialog, you should set DialogType property to FolderBrowseDialog, for example:
.radBrowseEditor1.DialogType = Telerik.WinControls.UI.BrowseEditorDialogType.FolderBrowseDialog;
Please refer to the attached project for additional information.
the Telerik team