Left shoulder pain, left side lumbar pain, one shoulder lower than the other? I'm a mess help!

Hi Guys, before i start thanks to anyone who reads and gives me any advice its much appreciated!

Ok so I've been suffering with a few symptoms for a while now on and off. I'm an Olympic weightlifter trying to iron out my imbalances as much as possible.

So I get lumbar discomfort mainly on the left hand side and mostly when sitting for prolong periods of time, I've had this for a while now but some weeks its okay and others it plays up more than usual. Its an annoying aching sensation.
My left shoulder also gets aggravated during my training sessions especially when snatching or jerking heavy and it doesn't feel the same as my right when i catch the weight and experiences more discomfort.
If i was to do a overhead press of some sort my left shoulder feels different and my left arm struggles to extend at the same pace as my right when using more challenging weights.
My left hip is defiantly tighter than my right but my left shoulder is more flexible than my right in internal rotation.
I also get a lot of stiffness behind my neck and sometimes into my upper traps.

When i squat i sometimes don't feel straight and as if i deviate to my left side ( I've been told this by onlookers as well ) so i favour one side.

I do have a slight anterior tilt in the pelvis but i am currently working on it with myofascial release, corrective exercise and just generally trying to improve my daily posture.
I took a photo of myself from behind and my left shoulder looks lower than my right.

I do also have flat feet where i stand more on the insides of my feet - I'm working on creating more arches all the time especially when i train (screwing my feet into the floor)

When i snatch sometimes i feel (and been told) that i ever so slightly rotate (well my body doesn't move) but from the side the bar looks slightly off which corrects itself once i stand up tall again.
My left elbow defiantly has a harder time locking out compared to my right under load and is less stable (sometimes when i jerk the elbow will lockout then rebend to lockout again)
Also when i snatch when kicking the bar (the hips meet the bar) i most always feel like it strikes more to the left hand side.

Anyone know why my shoulder has dropped? I didn't think it looked like scoliosis but my untrained eye is not great.
When i stand front on my knees are externally rotated as well.

I'm currently working on glute max activation especially my left side as my hip was tighter, i presume my glute max on that side would be inhibited?

Lots of information sorry! Just trying to be as detailed as possible and all these things running through my head I'm like aaahhh so many imbalances haha.

Thanks again for any help! I really want to iron out these imperfections and rid myself of pain!

I tried attaching the photo of me from behind but it doesnt work?