I'm not understanding what you are saying. Are you saying working until after 8:15 is perfect for you so that you'll never see your family? Or that you'll go back to work to eat after your kids go to bed?
Both sound bad
Both sound bad
I interpreted it as (non mandatory) social dinner's hosted by the company would start at 8:15pm.
I work 6am-10pm one day a week voluntarily, though I work for myself. I avoid traffic, parking is easier, and I get the office to myself without distractions for about 6 hours.
Also there's no concept of overtime with salaried fulltime employees. You might work 100 hours in a week and you're still taking home the same paycheck as if you worked 40 hours. That's just the way corporate America works.