Since my very beginnings with photon mapping, I have always had to change the intensity of radiosity when I ajusted the bounces. Do calculations for photon intensity change when the maximum bounces is changed in radiosity?

No. The exact same calculation is used. As photons are bounced, they do lose energy though. So, photons that have bounced, lets say 20 times do have an average of logarithmicaly 1/2 the energy of photons that have bounced 10 times if the photons did not completely lose their energy untill the end of their travel.