A terrible dinette table. Opinions on modification?

Rounding the corners, even an inch, or two, in radius would make a huge difference in comfort. Four small openings when the table top is in the bed position won’t matter. I’d just pencil in the radius using an appropriate round lid off a plastic container and use a belt sander to round it out. A little smoothing with a finishing sander, some dark stain on the wood and done. Keep it simple, and near no cost.