The software works great in your situation. We do it every day. It may be your workflow that is causing the issues. (I have my issues, but far, far away from AutoCAD, which is all you are really doing in this case)
So I did down load your drawing this morning and take a look. There are some 3D elements, so I would urge caution when selecting a UCS. Some of the dimensions were not at zero, but I couldn't perceive any twist.
I do have some comments on the work flow you described:
1. With you I don't think the surface information should ever be flattened. I am not a Surveyor, but as a Civil Designer, I never flip triangles. The data to make the surface should be correct.
2. Although it may be tradition at your company, I do not understand why you would explode the dimensions. This doesn't make much sense. Leave them be and see if that helps.
3. If your typical work flow involves dimensioning the building foot print, you my find it more handy to use a Civil 3d Label style. That way you can label the entire polyline with one click. This can be found in the Tool Space under Settings - then General - Multipurpose - Line (Create or edit a style and add the distance to the label) . Once the style is created in your template, you can label from the Annotate Tab - Add Labels Select Type "Line and Curve" Label Type "Multiple Segments" click add and it will annotate the entire line with labels that are annotative in Paper Space. (This is the power of Civil 3d) You can also use the Automatic dimensioning features of the newer version of Autocad to get almost the same results. I prefer the Civil 3d way because as the scale changes the text size changes in Paper Space.
In my experience, some survey firms can become a little stuck in there ways. I hope if you start to see the power of this software, you don't rock the boat to much (Why are you exploding dimensions?) It can cause problems with those stuck in R12.
Good Luck!
PS Feel free to PM me if you would like more information, although, a class would be easier than me.