Definately you will need a complete optical polarization on your training views, as you can read about me I’m not trained at all but I have followed many people who are and I exactly know whats wrong, when and why.
First of all I will assume you know yourself since your description is pretty good and you seem to feel yourself.
You will need to detone entirely, stop training the way you do and turn around to complete flexibility training with full yoga practice and diet rehearsal, you can folllow my other threads about this.
Then you will need to start again with velocity training (once you are able to complete the yoga wheel pause which will allow your pelvic and head joints to compress properly) with the powerball and the tool that you use to train your legs with it. Once you mastered the velocity on your four limbs on both right and left twists you’ll be able to have fun without worrying ever again.
What in the FUCK are you talking about? What’s with your new-age bullshit that you just blabber about in random threads?
To the op, if your technique problems stem from (in your opinion) flexibility issues, then start introducing flexibility/mobility training if you haven’t already. Sounds to me though that you know how to lift in good form, but it starts to go when the weight gets heavy. My advice is to train with good technique ever rep and not allow yourself to load up more without being strong enough to keep form. If you are diligent and don’t “ego load”, you will get stronger and stay healthier. Also, go over you DL cues, or let your partner give them audibly. Things like “Chest up” or “glutes tight” or something similar. Perfect practice makes perfect.
As for the knees/shins part, you might be starting the pull in the wrong place. Another reason may be that your extending your hips before your knees. By extending your knees initial, you’ll decrease the angle of your knee and allow the bar to come up in a straight line. Look at some DL diagrams and compare how you set up. You want to bar close to your shins or you’ll lose it out in front of you, but too close to your shins presents problems as well. Good luck.
Your lower back tightness is normal to an extent since your spinal erectors are greatly challenged by the DL, however, take a little self inventory when you lift and evaluate whether or not your actually using your glutes to finish the movement. Your glutes and hams are to prime movers in the DL, and if they’re not firing/being recruited properly, your lower back ends up taking the load. So remember to squeeze those glutes throughout the entire movement and to lockout with your hips, not leaning back with your spine. Alot of lifters end up making the deadlift a “backlift”. The hip extension movement is right, not a spinal extension movement.