This chapter further extends the research object to functionally graded spherical-cylindrical-conical shells, investigating their vibration characteristics under thermal environments with arbitrary boundary conditions. The theoretical modeling fully accounts for the effects of centrifugal force, Coriolis force, and initial hoop tension induced by rotation. The domain decomposition method is adopted for model analysis, and the continuity conditions between segments as well as arbitrary boundary constraints are handled using the penalty method. The validity of the approach is verified through comparison with finite element results. On this basis, the influence of the power-law index, temperature load, rotational speed, and geometric parameters on the structural vibration frequencies is systematically analyzed, and the mechanism of structural configuration on the critical speed is discussed. This chapter provides a theoretical reference for the design and analysis of complex spinning combined shells in high-temperature environments.