Problems printing thin walled objects

Hi All,
I am relatively new to 3D printing. I have been screwing around for a couple months on and off. I have been struggling of late on printing a cookie cutter. I am drawing in FreeCAD, slicing in CURA and printing on a formbot t-rex 2 printer with a .4mm nozzle.

There are two main problems that I was hoping someone could advise me on:

1) If you look at the first picture you can see the basic design that I am trying to print.

Attachment 10583

The second picture shows that the top of the cutter, which is .018" thick prints ok in some spots (blue) and not so well in the red spots. In the spots shown in red, it prints wider with extra blobs of material. This top surface should be just a single pass which I would think would be nice and smooth. I have printed this a few time with different settings and each time I have noticed that the back right and front left seem to print alright while the other corners seem to be worse. Any ideas?

Attachment 10584

2) In the first picture of the design, you are able to see that the inside surface is one continuous, smooth surface. When you look at the third picture, you see three defined surfaces, These line up with the changes in thickness that should only be seen on the outside of the cutter. I have tried to tighten the belts already and still get this effect. Any ideas?

Attachment 10585

Thank you for your time.
Thanks
Chris