Hi, you asked a couple of questions so I’ll answer them to the best I can in order.
Yes, when modeling in bender you need to make sure the normals are facing the right way so that the model is solid on the inside and won’t confuse the slicer.
Not sure what you mean by boolean operator because it’s been ages since I last used blender but you should use whatever tool in blender you normally use to add text to models and it should be fine.
As for screws, in my experience, threads for screws have never worked for me on screws as small as the holes on the raspberry pi. Self-tapping screws could work but they could split the plastic as you said. If I were you I would use M3 screws and nuts or super glue.
I have not used Makerware in around 3 years so I have no idea what degenerate, distorted and edge sharp are but I believe thickness refers to the thickness of the perimeter wall of the part. In that case, this doesn’t actually refer to how thick the model is but the thickness of the solid outer wall of the part. In most slicers, this is measured in shells and I normally have it at 2 shells. Basically, the amount of solid outer layers before it prints the hollow infill. You don’t need to make the part the same thickness as the perimeter walls.
I not sure how well I explained this so feel free to ask any questions.