1. With 5x5 at top weight you will eventually start to miss reps at the end of the final sets thus you won't be getting the volume in. Initially should work fine.
2. Makes the stress very large (nothing necessarily wrong with that) but logistically it just makes the H day super long.
3. Go ahead and swap out some type of fast pulling lift. Your body will thank you. 8 doubles every other minute if you are doing DE deadlift works well or just barbell rows 3x5.