If the spaces up stairs are being used, this will deter some of the fuckers who do inappropriate things up there. But if there are personal belongings and equipment there, then this will also attract more of the fuckers, and we have a duty to provide a secure place for these artists.
Unless we are going to have the building for a while, encasing the stairs and adding an extra door (which may go against some regulation or another), might be impractical. But can the doors be modified to make them more secure and less prone to being bashed in? If the balconies are going to be used much, then we might have to modify the doors to comply with something anyway.