Grounding problems with Cmoy in metal case

Okay so I decided to use electrical wire as insulator for the circuit board, however I did find this foam based stick on material in my house that was used in mounting a Air conditioner. Should I switch the insulation? 

The front panel components do they need insulation as well? I am using swiftcraft jacks with the plastic casing and the Rk097 (10kohm dual channel log pot) in this build. I am worried because the shaft of the pot and the metal part of the jacks is touching the metal surface. 

So as i was soldering wires to the panel output pins, 1 already came off. Are wires usually soldered to the pot/jacks? 

I just used 3 pinouts from the protoboard to serve as ground for the jacks/pot. Can I do that?

Thanks!

Will post pictures of the completed build once I am done. 

Thank you. I was referring to the wiper pins and the switch pins on the pot. I normally just coil the wire around the pin and then solder it. 

ISSUE! So I got everything wired up and completed today. After I tested the potentiometer and I put in the input jack wiring and then I got buzzing when I plugged the source. Now before the potentiometer and output jack were tested separately and they worked. Now the LED also stopped working. I found in my case excess leads that might have shorted sometings and a spew of solder on the R4 resister and the C2 and the R2 connected together. I took that out with the best of my ability. The buzzing still occurs, and when put my hand over the left or right channel pins their is a intense squeal (when it is turned on).

Now I took it out of the case. Wiggled the wires around and it started to work and the distortion went away. But when I put it back into the case the issue occurs again. But still doesn't explain why the led is not working.