temaire: I do not know if part (a) is correct, because I do not remember the formula. I will let someone else check part (a).
Your answer for part (b) currently looks correct. In part (c), you currently computed only the y-direction deflection and rotation, which are correct. But I think you now might also need to compute the z-direction deflection and rotation.
You accidentally typed 877, instead of 866, although you did not use it.
By the way, kN/m^2 is called kPa. Always use the correct, special name for a unit. E.g., 7214 kPa, not 7214 kN/m^2. However, it is better if you use 7.214 MPa, instead of 7214 kPa.
temaire: Your resultant deflection looks great. Regarding the resultant rotation, we would need to think that over for awhile. I am not sure yet. However, would you settle for just stating the y and z components of rotation? You might not need to compute a resultant rotation. Just state the two components, theta_y and theta_z (?).