looked to me like you were dive bombing those squats a little. you don't seem to have trouble with your lumbar curve... have you tried sitting your butt back, back, back, back, back rather than breaking from the knees? possibly (maybe) experimenting with a slightly wider stance? that might give you a nice tight squat that is easier to control into a position someplace just past parallel.
on the ascent... drive the glutes / hips through while pushing those knees out hard. harder than you were. they might even actually go out in an exaggerated fashion at lighter weights. should feel like your adductors would really rather not participate in this activity. that is as it should be, though, and as the weight gets heavier they simply won't be driven out that hard.
with the deadlift... i had a mental breakthrough the other day. instead of trying to pull the bar UP try and pull the bar BACK. yeah, that's right. push your heels into the ground and lean yourself back. you should feel like you are going to can over backwards (probably stagger back a few steps after locking out) anything that isn't heavier than you. actually, the harder you explosively drive it back using your bodyweight as a lever the heavier it will have to be to pull you forwards enough for you not to lose balance backwards. does that make sense?
i think there is a benefit to resetting deadlifts for each and every rep. the deadlift is a one way lift. UP (though aim for back). then get it back on the floor without wrecking your back and have another go at lifting it UP (back). if you don't reset between reps then you eliminate what is (often) the hardest part of the movement (that first inch). your hips also have a tendancy to shoot up a bit deloading the legs which risks fatiguing your lower back in ways that are unnecessary.
you have great ability to maintain your lumbar arch! your lifting looks safe, too. nice job.