There has to be an easier way to make this. I think B-bones would help but haven’t tried them yet.
To make the spring look realistic I used a bezier curve to control an armature with 255 bones. The bones were constrained with the Spline-IK modifier. The armature deformed a mesh using automatic weights and the ball at the bottom is parented to the lowest vertex of the bezier curve. All of the keyframes are simply the z scale of this curve. Learnt a lot about armatures and modes etc.
Impressive work. Maybe it can be made easier. But is all about the learning process. So to me this is impressive. 
Yes, there is an easier way, however that would include driver function. For the spring you can use a single circle and screw modifier along the axis of your choice.
For the spring to function you need only one bone and use the y scale (assuming the screw along the Z-axis) of the bone to control the amount of the screw in screw modifier function.
From there you can animate to squash and stretch by simply playing around the scale of the bone or for a little bit work, animate indefinitely by using its curve function of the driver. It’s a little bit complex when driver are involved but at least it will save you a lot of time in the long run.
Unfortunately this course doesn’t cover a lesson about driver.
Thanks FedPete for the encouraging words. Right now, as you say, it’s all about learning.
Thanks Robert for the detailed reply. I still have lots of basics to learn but simple scripts and drivers could be fun at some point. I will try the y axis and the screw modifier, sounds interesting.