1) Oh, not too much. Maybe 10 or 15 mins? I usually glance at what gets shared via Twitter.
2) No. I am so bad about this. Must improve. Too many croissants.
3) I try to wrap up by 7pm. I just made a rule for myself that says if I work past 8, I take a cab home. Sounds indulgent, but I hate spending the money, so it gets me out of the office at a reasonable time.