As with splitting a plate between two people, it's not something you'd typically see on a menu, but they're usually happy to do it.

Yes!!! You would be surprised what things you can negotiate in stores and restaurants. You need only ask. In restaurants you can even substitute unhealthy items for healthier items in your meal in many cases. Many local restaurants I go to even have items you can order that are not listed on the menu.

The branding is "right sizing". It doesn't seem to have gained a lot of traction however.

All the time around here - half a sandwich and soup for instance at lunchtime