The two stand out problems I can see are spine position related.
You're not doing a great job of keeping your back straight or generally avoiding spinal movement. When you squat you shunt your hips back by going into lumbar extension rather than a lovely hip hinge, and then your tight hips yank your spine into flexion. Having one of these issues is bad, having both is worse. Imagine all of the front to back and back to front squashing that you're putting your disks through, and smashing into extension like that means you're probably going bone on bone (huehuehue).
Solution: Think about spreading the floor with your feet and getting more external rotation in your legs while keeping your back straight at all times. This will give you more glute activation which will actually help unload your lumbar.
Your RDLs are kind of just poor partial deadlifts. You aren't keeping your knees back and your back isn't flat, which is causing you to over extend at lockout because otherwise you don't think the bar is in front of your shoulders. In reality, your hips and knees aren't fully locked out still. You also seem to be aiming for that glorious hip pop at the top. I keep trying to hammer this point home, but I totally understand people's misconception here...:
DO NOT AIM FOR A BIG HIGH SPEED LOCKOUT AT THE TOP OF A DEADLIFT OR SIMILAR EXERCISE.
Wtf, right? The problem is that the vast majority of people do not perform these movements with a flat back. Aiming to clatter the bar with your hip thrust with a bent back can seriously mess up the whole movement pattern and end up being a huge stumbling block to getting a fluid and strong movement.
What you should be aiming for, in order of priority:
1) A flat back
2) A braced core
3) Hip extension using the hamstrings and glutes
4) Keep your weight slightly to the rear of your mid foot (lifting the toes can be a useful learning cue, but a poor way to lift in general)
Those the important things for getting the right training effect (posterior chain activation and spine neutrality prioritisation). Smashing the bar with your hips is a product of getting that stuff right, and you can't get that stuff right by aiming for hip pop first. Make sense?
Your pendlay rows would also benefit from a better spinal position, but you need to think about your shoulders too. You are actually internally rotating and dumping your shoulders forward and up (towards your head) at the top. You want slight thoracic (upper back) extension, while keeping your head and lumbar neutral, and you need to keep your shoulders neutral (not quite pinned back) and squeezed down towards your back pockets.
Well that was a long post. Enough for now. You're welcome.