I would like to know if there are any other ways in which photon's are being emitted other than in the case an electron's orbital around a nucleus changes.
Yes. There are loads of physical processes in which photons are created. It won't be possible to list them all out but well known examples are matter-antimatter annihilation (e.g. electron-positron annihilation, at lower energies.), the acceleration of charged particles, radioactive decay (notably, Gamma Decay), etc.
That's a give and take. The emission of photons is always based on an energetic level of particles higher than the surrounded world. To reach this higher level it needs an receive of photons.
A moving electron will be deflected in a non parallel to the movement magnetic field and emit photons. How the electron reach the kinetic energy for this propagation? By electromagnetic interaction with other particles. Photons are responsible for the increasing kinetic energy. And they give this energy back in braking situations. And also in the form of photons.
So the change in orbital of an electron is only one possibility to recive or emit photons.