I watched a video by BV3D about using ferrules on the wires of Creality printers and others. The power, hotend, bed heater wires are all tinned and then clamped. His explanation was that the heating and cooling would cause the wires to become loose over time and cause problems. Didn’t sound like a bad idea but the ferrule kit with the crimper was $27 probably a life time of ferrules unless you have a bunch of printers. What’s your thoughts on putting ferrules on the above mentioned wires?

I think the ferrules is the proper way to go. Give an excellent (when properly done) connection and does not cause a problem with possible breaking of the wires when tinned due to flexing of the joint. Its also easier to thread the wire into the ferrule then it is to push it into the screw terminals:})
Most “professionals” that I have run across recommend against tinning of the ends of wires.