The Chlorine generator doesn't have a check valve. If it's flow switch malfunctions and it's power source is other than the pool pump, chlorinated water could back flow into the heater's copper heat exchanger and eat it. Additionally, hydrogen gas could potentially form and collect in the cell. You would have a Hindenburg on a smaller scale, of course, but if someone was working there...
I STRONGLY recommend the cell be placed much closer to the ground and a check valve or Hartford loop be set behind it to prevent the previous scenario from being possible.
The capped pipe in the 1st picture appears to have a notch cut in it. This is for the spa jets and will allow air to be drawn into them, increasing the pressure felt when they are getting the full return flow from the pump.
I agree the setup for sending water to the spa when in circulation mode is less than ideal. A valve should be added there and union ends added to the check valve for easier replacement when that time comes.
Welcome to parenthood. You are now the proud caretaker of an artificial life form in your back yard. It has a heart, kidneys, veins, arteries and limited intelligence. It needs to be fed and cleaned or it will get sick. Fortunately, it doesn't require as much attention as a child or pet though there are occasions when it it cost like them. We'll help you keep that part down.
Scott