Tempted to buy a stock head at this point. ugg.

I bought the car with no factory head unit and a poorly wired (correctly run, poor connections) GMOS-6 and AWCS.
With the faulty wiring came BCM issues, so I rewired it. No issues since.

Then I run out and grab a kenwood bt358u. I clip off the harness to whatever aftermarket head this guy was running and wire the ground/hot/ign lines and get the unit to fire up while the accessories have power and turn of when accessories lose power. I then wire up the dev power (to the ant power and what I assume is amp power, despite that seeming unnecessary) and connect the remote control line to the awcs and attempt to get the AWCS to reprogram to my head. After realizing that I need to check online to see which of the two identical holes to shove a pointy thing in to start the process, I disconnect the remote line and tape off the ends to avoid ant potential issues from shorting.

Note, there are 7 monster cable looking plugs in the hole where the head belongs. One wired directly to each speaker except the front center. <-onstar speaker?
They look like they were added at the same time the GMOS and whatnot was put in. Presumably to bypass the OEM Amp?

I try plugging the door speakers directly into the head (vga style plugs) vs attempting the harness. (damn 4 channel head)
No sound

In fact, I can't seam to get sound out of any speaker. I'll check with Kenwood to see if there is something I need to do on the head to change the outputs.

Why I am posting here is to ask if it is worth it to just attempt the harness to wire the sound and only plug the big center in to the head as a sub, or should I stick to the vga style plugs on the back of the head and the direct wires to the speakers?

I suck at car audio.

Everything works mint but the sound.
The kit was installed when I got the car.

I repeat, my only issue is getting sound to the speakers.

What I am looking for help with is deciding; Am I going to attempt to wire up the sound through the harness, or try using the direct leads to the speakers that I think the prev owner added?
Looking at crutchfield, one needs to bypass the bose amp on the bose equipped devilles, but not the OEM amp on the non-bose devilles. How do I tell if I have a bose system? Easy, look at the non-existent factory head unit. Bah. I could call a dealership and have them look it up by vin, I guess.

Something else I just noticed. There are 4 of the monster cable looking plugs coming out of the GMOS-6...