FRONT SQUAT - not bad, but really try to get that torso as upright as possible. the knees have to go way over the toes so don't be scared of that. work on ankle and hip mobility/flexibility, do yoga (i believe in it), and just keep front squatting and eventually you want to to get that stretch reflex/bounce out of the bottom when your hamstrings touch your heels. sit your hips right in between your heels while pushing the knees out over the toes. always keep the chest and elbows up.

BACK SQUAT -  it almost looks like your sitting back a little too much like a low-bar powerlifting type squat. remember the torso stays upright but not as much as the front squat will. the knees a tad bit over the toes. If you look at the end of the barbell at the bottom position of the squat, its way over your toes, out of the base of support and it should travel in a straight line staying over your midfoot the whole movement. if you push your knees out past the toes and bring the hips closer to the heels, you will have better balance.

I am 6'3" and prefer a slightly narrower stance for my front and back squats, because im tall my knees go way way over my toes in order to keep the vertical torso

Not exactly sure about how the knees  have to go over the toes, this could be a lack of ankle/hips mobility.