Hey, I like your boat, nice work. You will find that a smaller hull is quite suseptible to changes in weight, weight distribution and changes in the center of gravity. You will have to test your specific setup(s) to find the best solution. I used swivel seats mounted to the the benches without peds. Since I like to sit to starboard to run the tiller, I mounted the aft seat to that side. The boat will tend to lean in that direction. So I used heavy items like anchors, battery and the gas can to offset the list. My second seat is mounted on the front bench in the center. This keeps the hull level and affords the driver a good view of the water ahead. I kept the middle bench open since I have under-bench storage, and to allow me to row whenever is like...which I enjoy. If you are ok with center-mounted seats, that will provide the best center of gravity. If speed is a consideration, seat location can have an impact on that as well. There are some pics in the link below showing how I placed my seats. Since you have the seats already moounted, I would take her out for a test run and have some fun.
Rick