Submitting expected hours
Depends on what they're going to do with it. If they're using it to budget for your expected labor, expect the most hours you can get away with so you don't have to worry about them telling you to cut back if you've exceeded your "budget", and if you work less than expected/budgeted no one is going to complain. If it is to determine who is the 'most expensive' and therefore who to get rid of, just say 40 hours a week and stop working when you reach that limit and if they ask why you weren't working Friday tell them why - "I submitted expectations for 40 hours a week, so I didn't think I was allowed to exceed that".
When you get weird questions like this, you just have to figure out why it is being asked. Then you'll know how to respond.