Remove the jaws and route the edges that you could not route while they were still attached. Then use a roundover bit on all of the corners except the inner edge of the inner jaw of the end vise. Give everything a lite sanding, and apply Danish oil to the inner surfaces of the jaws. (By "inner surfaces", I mean those surfaces that will not be accessible when the vises are assembled - the inner surface of the inner jaw, that bolts to the bench, and the outer surfaces of the outer jaws, that bolt to the vise plates.)
Mine is similar but a bit more robust. The top is a sandwich, two 18mm sheets of WBP ply with an 18mm mdf filling. The legs are mortise and tenoned together, the ends glued and pegged, the stretchers are joined with long bolts so it comes apart. I stiffened it by adding a very closely fitted cabinet underneath (it had to go in dead square) and it is now absolutely rock solid.
The next day, cut it flush. Use a block plane to ensure it truly is flush. This will be the top of the bottom layer of the bench top, so gouges aren't a problem. (Wiping up glue with a damp cloth can lead to stains and finishes applying unevenly. That won't be a problem here, either.) But bulges and bumps are a problem - they will keep the two layers of the top from matching up evenly.
While a strict figure for the bench’s weight capacity is not available, a quick browse through their other stand and bench products shows a general weight capacity well above most other brands. As such, while we cannot say for certain that this bench provides the best weight capacity, it is more than likely that it the capacity is similar to the other products in the catalog.