Hey man, good on you to post this vid!
You're holding yourself accountable for your own improvement, and that adds major bonus points to your technique.
So, just some thoughts for you:
1. It appears you're working striking for MMA, and not Muay Thai specifically. Some of what I say may not apply (coming from a Muay Thai background).
2. Even for MMA, there is way too much forward lean coming off your combos. Particularly your combos that end with body. This, combined with your hand position after throwing, leaves you susceptible to knee to the grill, big uppercut, hooks, etc. You get the point. This is one biggie I'd work on fixing first. For MMA, it's good to be seated lower in your stance, as opposed to the more straight-up stance in Muay Thai, but being seated low AND leaning forward leaves you with far less mobility.
3. Your kicks, even when shadow boxing, should never control you. You control the kick. Don't get in the habit of spinning in a full circle after your kicking techniques. Focus on controlling the motion, activating your full body. If you're facing the 12 at the start of your kick, you should ideally be facing the 9 when you land. Then, you can punch out into your original stance, throw switch techniques, or just circle around. If you can control your kicks while shadow boxing, you'll do the same in a fight. Notice great K1 and Muay Thai kickers throw with brutal power, but if they miss, they're not relying on sloppy spinning back fists, etc. They're not being thrown around by the kick, so even on a big whiff, they land in a position to immediately throw more bombs, without ever exposing their backside.
4. Your elbow movements cause you to telegraph your punches. Your elbow moves first on a lot of your punches. And when it's not moving first, it's sticking too far out. Keep those elbows in to protect yourself, in addition to making your striking less predictable, faster, and cleaner.
5. When throwing knees during shadow boxing, try not to move forward with the knee. In other words, let's say you're in your southpaw stance throwing your left knee. Throw it, focus on toes pointing down, hips out, then pull it right back down into your original stance. This will make your knees more powerful, and you'll feel more solid when you do throw moving forward.
Those are the big things I see. Take none, some, or all of this advice, and apply it to your training however you see fit.