Not that i can think of other than you will get tired quicker. After you get it up you will expend energy helping it go back down slowly. But i noticed you where using normal plates. Does you training facility offer rubber plates?
Once you get into heavy lifting you will never want to "help" it back down. I remember when i first pulled 500 for 1 rep when i got it up my brain went " good job, now let go!!!!!!"
Until you get to the power lifting stage, I recommend a two count down (or with gravity), and a one count up (against gravity).
Why? It all has to do with eccentric (muscle lengthening) vs concentric (muscle shortening) muscle contractions. It's believed that more micro-tears to the basic functional unit of muscle occur during eccentric contractions. Eccentric contractions typically occur when moving with gravity. Additional to this hypothesis is that these micro-tears stimulate the body's response to build more muscle. So while you are in a strength/muscle building phase of your training, emphasizing eccentric muscle contraction is beneficial because you are maximizing that micro-tear response.
As for critiquing your lifts:
Squats: My only concern here is that I observed a bit of a "bounce" at the bottom point of a couple of your repetitions. Bouncing places an undue amount of strain on the tendons and ligaments, particularly at the knee, and uses the spring force of the muscles, ligaments, and tendons to assist the up portion of the squat, essentially cheating the lift. It only happened once or twice, but just something to be aware of. I also concur with previous recommendation to close down your grip on the bar in order to create the "deltoids shelf" on which to rest the bar.
Deadlift: As you progress through a set, I noticed that the weights were coming down before your butt and waist. This is significant as it means that your back is supporting more of the weight than your legs are during the down phase. Keep the weight moving at the same speed as your hips. The weights shouldn't hit the ground before your lower body reaches the end of the down-phase of the lift (ideally, it happens at the exact same time).
Dumbbell rows: This is more of a personal preference for me, probably because I've sustained a critical neck injury in my life, but if you are able to maintain your posture in doing so, try to focus on a point out ahead of you on the floor, not on your reflection in a mirror. It is a more neutral and comfortable position for your neck and head. That being said, form is everything, so if you need the immediate feedback from the mirror, then go with what you're doing.
Knuckle push-ups: As already stated, you have too much arch in your lower back, which is likely resulting in your raised butt. Compare to doing abdominal planks, where you suck in your abs, flatten your back, and hold that position. That is the posture that you should still strive for during push-ups of any sort. By pulling in your abdominal wall, you help to flatten your back which will in turn flatten your body.
Keep up the good work and best of luck on your program!