f1 = 1, f1.2 = 0.8333, f1.4 = 0.714... so on and so far, try remembering from f1 all the way to f32... another alternative would be to remember the physical size, and most of us have stated in previous post, it is impossible as different focal length have different aperture size even if both are at f2.8.
for the blue parts, there is no way, it depends purely on the effects u want, and if there is a way, it is impossible except for the world "brainest" guy, the combination of different focal length, focusing distance, aperture can easily result in over millions of combination.
eg. a 50mm lens at f1.4 give xxx DOF(area in focus) when the user is 1metre away, but it will change to yyy DOF when the guy just take a step further or away from the subject.
if u think it is complicated, im sorry but photography is not for u. just get urself a PnS and leave all setting to the camera.