I would not be too pushy about the friday night subject, but i would see if the guy answers my phone calls on friday nights. to me, that would be the red flag – is he available at 11:00 pm for the “last phone call?” If you call him at 10 or 11 in the morning, or even earlier if you know he is up that early, does he answer? If you get to know his address, is it ok to pop over unexpectedly (presumably with coffee and donuts or something)? or is he totally unavailable by phone certain times, or his house is totally off limits? if you want to do something on a saturday morning or whatever, is he available, or will he make excuses?
i would ask “where have you travelled to?” and if he was ever married, does he have kids, are his parents alive (all things good to know and easy to ask in casual conversation). this way, if he says his parents are alive but he never takes you to meet them, that could be an issue.
I am the “update lady” and I always ask people to please feel free to post an update if they wish, to let us all know how things went.
i would keep all questions really casual, not pushy, but i would just be on alert for your intuitions.