I need to mark up some drawings of plastic enclosures I'm using, to precisely indicate where I need holes and cutouts made. The enclosures are made by POLYCASE.COM, and the company has sent me DWG based drawings of all the enclosures I'm using. I should say I'm an electronic designer and totally new to Draftsight. In fact up to now all my markups have been printouts of the enclosures with my added holes and slots hand drawn in (I mean pencil and paper). I'm progressing through the tutorials and at this point wanted to ask some opinions as to whether or not Draftsight will likely help me accomplish what I need to do. Let me explain my concerns briefly.

The enclosures are "nearly" simple rectangular shapes. I say "nearly" because the side edges all have a slight incline, so that along any one dimension the tops of the enclosures are slightly less than the same measurement taken at the base. As such, all the location measurements for holes and slots on my hand drawn pencil drawings are based on measurements taken from topmost points on a given LEFT edge. (for the X dimension) and from the top for the Y dimension. So, to define a hole on the DWG file, draftsight will have to...

1. Let me switch the drawings measurements in millimeters to the inches, so I can work with my own measurements.
2. let me pick, mark, and save arbitrary points at various upper left extremes on each "view".
3. Allow me to measure precise X / Y distances from such points to temporary (construction layer?) lines indicating where a cut or hole origin will be placed.
4. Create my shape at that location, or in some cases a series of holes or shapes, starting at that reference.

This all "seems" do-able, and might be pretty simple tasks for someone more experienced. But being new to this kind of CAD and certainly new Draftsight, I figured I'd better check before I invest more time. The fact that the sides are "inclined", and not at right angles to the base has me a little concerned. Especially since i doubt the original DWG files were created with Draftsight.

Any thoughts or insights appreciated!