There's a lot of room for improvement. As is she is good as a PD ship, nothing more. Maybe can fend off an Isanth or two. Definitely not a frigate, more like a very small corvette.
Design-wise she's basically a quickly and crudely welded hull for some leftover turrets from other ships. No design put into the ship herself, no work put into making her look like a proper ship, not just some barely compatible parts put together. Actually if I were youI'd reassemble her from scratch instead of trying to improve this hull.
Why 3 stars? She's working with new power - first and second star. She has a function (maybe not the function you chose for her - but still...) - third star.