Hello again! It makes it really hard to help make Slic3r/part orientation/design recommendations without being able to see the part/model. If you prefer, you can send in a render of the item, or a screenshot if it helps. Designing models to be 3D printed rather than injection molded or 2-5 axis cnc’d can be quite different. If you prefer, feel free to contact us at 970-377-1111 and describe your part over the phone so we can offer some tips/guidance.
Are you using a fan? Active cooling will help overhangs, bridging and printing in the air.