STL / CAD Cleanup & Prep for FDM 3D Printing

Description I have an existing 3D sculpture that I've already printed twice on a Flashforge Adventurer 5. I'm looking for someone experienced with preparing CAD/STL files specifically for FDM printing. I’ll provide the original file plus photos of my previous prints showing the problem areas. I need help with: Inspecting and cleaning up the model where necessary. (Mostly the thumb and the layer lines I'm getting are slightly too visable. Adding a wall-hanger/keyhole insert to the back (already included in the file but not installed correctly). Fixing a crease/fold around the thumb. Reducing pock marks and overly visible print lines, especially on the palms and back of hand where the scaffolding supports connect. (my goal is little to no clean up on the contact point's after separation. Recommending better orientation, supports and slicer settings Making sure the final file is watertight and ready to print Important: I don't expect every problem to require changing the model. If something is better solved with supports, orientation, layer height, or slicer settings, I'd like you to tell me rather than unnecessarily modifying the design. I'm looking for someone who actually understands FDM printing, not just 3D modeling. Thank You!