Printing Thin Walled Objects

Hi Folks, I am relatively new to 3D printing. I am printing on a formbot t-rex2, using CURA as the slicer and FreeCAD for the modeling. I am trying to print cookie cutters and I am having some problems that I was hoping that you might be able to help solve.

If you look at the third picture, it gives you an idea on some of the dimensions. But I am basically printing around .020" to .030" thick using a .4mm nozzle. In the first picture what I am showing is that the quality of the print is good in the back right hand corner and the front left hand corner (blue arrows). In the back left and front right, the quality of print is poor. When I say poor I mean that the thickness is not maintained well and it gets bumpy. I have purposely modeled the thickness at around.018" thick so that the top section would only print with a single width pass.
Attachment 10615

The second problem is the inside surface is designed as one continuous smooth surface (see model below). If you look at the third picture, the inside (as printed) is not smooth and the three changes in the surface align with the changes in the thickness which only applies to the outside surface of the cutter. No sure why this is happening.

Attachment 10614

Attachment 10613

I have been playing around with many setting and made sure that my belts are tight. What should I be look at to resolve these two issues?
Thank you
Chris

Yeah, im doing 3DPRINTING SERVICE in Vietnam. And Thats typical situation. You have 2 options to follow:
1- Edit the wall thicness ( in 3d design soft)> 0,8mm
or
2-Change the manual nozzle's diameter ~0.35mm

cuz my English is not good, so I cant not explant more :/
if posible, I can slice it ( to Gcode file) for you, based on your 3dprinter and the favourite material!

By the way, This is my GPluschanel, add me into your circle if you find it useful <3 Dịch vụ máy in3D: https://plus.google.com/+Taomau3d-in3D-taomaunhanh