as long as the amount of consecutive days you train is limited things should be fine.
again, a concern might be down the track when your squat gets pretty big it will be too much volume to squat the next day. when this is the case change the monday squat to front squats, but you'll have to do the program for a while to know when to make this change.
Core work (either sit ups or proper hanging leg raises) is always fine, just keep it limited to 3x15 of ONE exercise at the end of each session.
Arm work also isnt a bad idea. Keep it to the friday and only pick ONE exercise for biceps and ONE exercise for triceps. 2x10 is good for each. I like barbell curls and skull crushers the most for arm work.