It is all relative. A few pictures would help so we can see the style of the home and the area you would like the rug in.

Not enough information. How big is the room? what size table? how many chairs? what else is in the room? how does the dining room relate to the rest of the first floor? what does "casual" mean--lots of styles are casual. And yes photos would help immensely.

I really dislike rugs in DRs and for sure with kids . Waht would be the purpose of an inset that would mostly be hidden by the table .