I agree completely that you do not want to put the divider up. These cages are on the small side and putting up the divider just makes the cage choppy and doesn't leave any space for running room.
If you would like a kitchen area you can buy coroplast and make a litter box insert for the cage.
The cage is not 9 square feet though. It measures 24 inches by 47 inches which equates to 7.83 square feet. This is fine for pigs that get along well but it is not huge.
I personally have 2 Midwests and they work well for what I need. I have a pair of sows in each cage and do well. You need to be sure you don't clutter their cage so that they have places to hide but still have plenty of space to run.
For bedding I have fleece liners and I have litter box made out of coroplast for their kitchen which I put yesterday's news cat litter in. This is a great combo and it is what works best for me. Using loose bedding in a Midwest is a pain because the sides are very low so i wouldn't suggest shavings or carefresh for the entire thing.
The cages definitely NOT sturdy at all, my 10 pound foster cat sitting on the lid almost collapsed the whole thing in! I live in a rental house for 8 months of the year and the Midwest's are my school cages. When I'm home for summer I have stacked 2x4 C&C's because the Midwest's would not stand up to my animals. At home my family has 6 cats and a Jack Russell, all of whom could easily destroy the flimsy cages.
Here are some pictures of my set up just to get some ideas.
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