Can the planting of new bushes in the same position as those that are being destroyed with the dreaded BLACK SPOT be detrimental to their well being.????
yes, black spot spores can linger in the soil. There are some soil treatments to eradicate it. More information is at the American Rose Society: http://www.rose.org/blackspot-the-hows-and-whys-of-control/
Are you planting resistant varieties?