I rarely listen to video checks, although I am okay with Britney, especially Britney of more recent vintage. Till the World Ends is a pretty good tune. It is particularly interesting for a pop song because the chorus is really strong, but doesn't full drop until 2:45. That is big deviation from the pop song play book. Further, the work that went in to that video is nothing short of immense. Britney is a talented performer. Her voice is not as pleasing as some of her contemporaries, but she makes the best of what she has. I probably like Rhianna better, but I have a soft spot in my heart for Ms. Spears.
Yes, my friends, we don't just comment on squatting videos here. We also discuss pop divas and heavy metal in this forum. Those two genres mix well together in my opinion.
I only watched your deadlift in keeping with the sticky policy, but I do have some commentary. You need to get tighter on the deads. Your footwear will not make you hold your spine in extension. I would keep the lifting shoes. You need to squeeze your spinal erectors harder and you need to get tighter off the ground. You let everything go as you apply force to the bar. A coach would definitely help. While he is no longer a Starting Strength Coach, Alex Cibiri out in Mississauga knows this stuff and can coach it. Look him up. Also, try the exercise from the Zach video. It won't hurt.