Deadlifts should be put for one of your leg days (hip dominant). The volume of this workout is extremely high for 5x5. If you can get through this workout with 80-85% of your max on all lifts, you are Superman. Also, it's not competely balanced.
Besides the front squats, the rest of the workout isn't that great. There are far better exercises than leg extensions and curls.
Compare this workout to the day before it, and you'll see how unbalanced it is. I understand that the 3x8-10 days are "easier" days, but you're pounding the upper body again and hardly doing anything for legs.
This is the only good workout you have listed, but I would still make changes. It's primarily a quad-dominant workout (squats, lunges, step-ups) and you hardly do anything for hamstrings.
I'd revise the workout and cut down on some of the volume on your 5x5 days and balance out the entire workout.
And stay away from the Smith Machine.