No earlier than 4:45pm please as there will be a small/private ceremony prior to the reception starting at 5pm.
YES! By all means bring the kiddos! There will be plenty of food and drinks for them, they're part of the family too :)
YES, please see the "Travel" tab for these. In Omaha there are some better hotels/areas to stay in than others. It is NOT suggested to stay at the ones that are on 72nd just north of the interstate (I-80). There is one nice hotel just a block north of the venue in Ralston (by Ralston Arena), then a few others in the Aksarben area (about a 10 minute drive from the venue).
Just north of the venue at Ralston Arena (Liberty First Credit Union Arena), there will be an Omaha Lancer hockey game Sunday evening. This can make traffic on 72nd busier, but typically it's not horrible and still flows rather smooth, especially for the Sunday games.