Laputa Robot

Hello All,
This is my first ever 3d model. I used Blender to create the model and there are probably a number of problems with the result. I would appreciate any feedback regarding the topology or other things I could do better.

When printed I had an error around the lower hip area and where the outer skin of the print did not come out. I am not certain as to whether this was a printer error or a model error.

Let me know what you think!