Your hands are locked in against your thighs/box. Your first movement (probably subconsciously) is to jolt your hands out and away from your body to give your hands and bat enough room to negotiate your legs/body in order to play straight. It's good that you understand the need to play with a straight bat but you are overcomplicating it for yourself by forcing an unnecessary hand movement before every ball. I see it a lot and it is a relatively easy fix, once you are aware of it and review footage of it a few times it should be something you can stop yourself doing quite quickly.
Relating to an above comment about where your bat is pointing, it is not overly important unless it starts to point over leg stump or towards fine leg as this will close your hips and shoulders off making it very difficult to play straight and off your pads. Which guard you take has almost no bearing on where you should hold your bat, so ignore that advice in my opinion.
I agree your bat looks a little cumbersome, but this could be due to the aforementioned issue with where you start your hands.
Your head is tipping over to the off side almost by default for front foot shots, its hard to tell from front on but it looks like your feet are pretty close together in your stance, spread them a little and stop bouncing around as much pre shot, this should settle your head/shoulders and allow you to remain more balanced.
There is advice above to stop dragging your back leg through after the shot, but no advice on how, or why you are doing it in the first place. Usually when i see someones back leg come round and end up square on or even in front of their front leg, it is because of a small stride to a front foot shot and the head position causing you to topple over your front foot. There are a couple of occasions where this happens and the more spread stance i have mentioned may help here.
However it appears that you are often taking quite a big stride and striking the ball pretty well but still ending up square on despite no obvious balance issue caused by head position. This is usually down to a fundamental issue with how you strike the ball. You are almost certainly allowing elements of the left side of your body to influence a front foot shot much more than they should do. It is hard for me to establish if you are playing with more bottom hand dominance than you should be, but the entire left side of the body needs to be considered. If you open your left hip/shoulder up either as a result of overly dominant bottom hand play or to facilitate it, then you will always cause yourself this problem of ending up chest on to the bowler with your back leg level with your front one. A front foot shot should be executed from a relatively side on position with the top hand on the bat leading the way, the bottom hand comes along for the ride, it shouldn't be the hand dictating the power/direction of your shot.