Hi! Many thanks for sharing the design! I took a quick look. The undesirable intersections are rampant on the model. It will take lots of efforts to clean up. I personally think it would be better to recreate it from scratch using Surface Modeling technique.
The intended model is thin body generally. Usually, the designer would focus on exterior shape first without worrying about interior details. The Solid Modeling approach forces you to consider exterior geometry and interior geometry at the same time. You end up having to clean up detail mismatched intersection by using lots of Delete Face. I don't think this is the right approach to tackle the design.
I would first create the exterior surfaces. Stitch them into a quilt and thicken it to the desirable thickness. Then add detail geometry on the interior side. Delete Face is more like a clean-up tool of last resort. It should not be used as a primary design tool. When it is used extensively, it usually means something isn't done right.
Thanks again!
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer