I only watched the 45 and 245 videos. I wouldn't worry much if you were training in my gym. I would only say the following -
1. On the warmup w 45, you're actually trying to sit too directly straight down with the hips initially. Your movement down w the 245 is more natural and that's what you should try to emulate on your warmups.
2. When you stand on the heavier weights, work on not pushing the knees back so far - this will be unavoidable to an extent as it gets heavy, but that push back will force the trunk to lean over for balance. It's pretty minor in our case and really only even stands out in the last rep of that set. Basically work on extending the knees and hips together rather than leading w one or the other.
Overall, though, this is a good job and I definitely wouldn't lose any sleep over it.