New Water Softener/RO Disaster Pressure Release Tank?

Finally started re-construction and the water softener company came out to replace the old unit. The new water softener does work, but, the installed a Pressure Release Tank and it is suspended in the middle of the pipes(not mounted to anything)

Are these Pressure Release Tanks really code in Michigan?
Why? I am on city well water and actually have low pressure.

Also, they changed all of the copper pipe from 1 inch to 3/4.

While we were already being stupid and paying too much money for a water softener, we decided to go Full Tilt Stupid and got the RO, too. The RO is supposed to be a 75 Gallon Membrane with a 3 Gallon Tank. It is so slow- do I need a bigger tank or a pump? It is mounted in the basement directly below my kitchen sink in the ceiling and also is plumbed to the refrigerator/ice maker about 10 ft away.

Any and all guidance is appreciated. I know we already made some expensive mistakes.

Michelle