Hi Justin,
Ok, i don't have long so i might post more later...
Basically it seems you have a lot of different and conflicting opinions. The back exercises sounded like they helped your back but not your pain - it is not good us fixing things if it doesn't solve your problem, right!?
No what the chiro said sounds plausible in that your right sided muscles may be overactive. I am not sure if this is from the genetic thing. However, i do see a lot of people who have overactivity as a problem and it gives them pain.
The most interesting thing you mentioned in the post was that you only get the pain after exercise when you sit.
You see, I am thinking that you have what is classified as Non-specific low back pain (judging by your pictures) with a classification of motor control impairment - active extension. What this al means is that your muscles are way overactive and squashing your ribs, spine, pelvis and hip.
Think of it this way, when you squeeze your hand, especially the knuckles like in a handshake, it doesn't hurt that much right? But if kept squeezing and squeezing all day, by the end of the day, that hand is going to be very sore [sorry - it works better when i am with you in person!!]
The same thing is happening in your back (I am only guessing ok). The muscles that are overactive are putting extra load onto the joints and bones and then the weakest areas start to hurt first.
I asked the questions about motivation because people who are highly motivated tend to have this problem more in my experience because they persist with exercises, even when it hurts whereas people who give up easily have a different type of classification of back pain (again in my experience).
I wonder what happens when you lounge around being like a slob - do you ever do it? How does it feel?
Are you conscious of your posture? When you try to stand up straight, do you feel tired from holding the position? Do you feel good when you slouch? Do you feel bad when you catch yourself slouching?
It will be interesting to see what is wrong...Are you able to post pictures of your posture from side on, the back and the front please?
Thanks!