Yeah done it before, a while ago though, easy enough to do. 4 days a week isn't hard at all if you're eating right.
Depends on the body part, on my leg days I pretty much just squat then either take off my belt and do more squats or front squat with some lower back extensions and hanging leg raises thrown in at the end of the day. For upper body days I like a lot of different movements, more so with back whilst working up to 1 top set. Why do you have a day just for your lock out?
Cool. I'll try it out then.
It's not really a day devoted to lockout. The first movement, paused bb bench, is just swapped for board press. It's for strengthening the triceps and building up the psychological aspect of holding a lot heavier weights for bench. The assistance is still full range db presses and the like.