You can hide standard elements from editors in this way

[InitializableModule]
    [ModuleDependency(typeof(EPiServer.Web.InitializationModule))]
    public class HideFormElements : IInitializableModule
    {
        public void Initialize(InitializationEngine context)
        {
            Type[] formElementsToHide = new Type[1] { typeof(TextboxElementBlock) };

            var contentTypeRepository = ServiceLocator.Current.GetInstance<IContentTypeRepository>();

            foreach (var type in formElementsToHide)
            {
                var contentType = contentTypeRepository.Load(type);
                if (contentType.IsAvailable)
                {
                    var clone = (ContentType)contentType.CreateWritableClone();
                    clone.IsAvailable = false;
                    contentTypeRepository.Save(clone);
                }
            }
        }

        public void Uninitialize(InitializationEngine context)
        {
        }
    }