No part of any mobile home development shall be used for nonresidential purposes, except such uses that are required for the direct servicing, recreation and well-being of the residents and for the management and maintenance of the development and are not otherwise prohibited by any provisions of this article; provided, however, that a convenience commercial center may be allowed by the governing body if no similar use exists or is actively proposed within one mile of the mobile home development by accessway available for use by the general public, and the applicant demonstrates to the governing body's satisfaction through a market study that such use is justifiable and will be supported primarily by the residents of the mobile home development; such market study shall be conducted using the standards outlined in § 300-508. No such commercial center shall be opened until at least 50% of the dwelling units in the mobile home development are occupied. Signs, parking requirements and similar factors shall be controlled by the same regulations that apply to commercial uses located in other zones in the Township. In addition, the maximum number of residential dwelling units permitted on the tract shall be reduced by one for each 8,000 square feet of land or a part thereof devoted to the convenience commercial center.