I think you are outside the limits of a Caesar II analysis since your material is not linear elastic. In addition, I doubt whether realistic Young's Modulus and Poisson's ratios could be obtained.
I would not take any axial and bending stiffness into consideration for the sake of your CAESAR II modelling. The behaviour of the rubber hose and bend like yours will behave similar to expansion joints with ignorable stiffness.
Do not forget that you need to provide adequate supports for this type equipment on the piping since it does not have required stiffness.
I would not take any torsional stiffness on the rubber elbow either. Just watch the rotations on both ends of the rubber elbow. If you think it is required you may need to provide rotational support(s) on the pipe(s) connected. I would ask the vendor about the rotation that the rubber elbow can handle without any problem under pressure.