I can't speak for other programs, but I'm almost sure they would be the same. In AutoCAD there are drop down boxes to set line type, color, and thickness. And you can turn the display of line thickness on and off.
There are libraries of textures for various surfaces (concrete, sand, wood, etc.) and you can hatch a closed surface with them, or a solid color. As for the little triangles, it's very easy to draw ONE triangle like you want and make it into a block. Then you can simply insert it at specified rotations and scales as you need it. You can EXPLODE blocks to restore them to simple drawings.
As for laser cutting, I suspect most cutters can accept DXF files; I've submitted laser cutter DWG files in AutoCAD 2000/LT2000 format with some specific rules (the cutter will typically supply a sheet describing them). You typically don't have control of the width of the cutter beam, as I recall it is typically .006 wide, but some lasers can use a "low power" setting to write laser text (almost never done, I think). Also, most lasers won't cut balsa well above 3/8" or so thick, due to power settings.
Your laser cutter drawings need to be clean. That is, no duplicate lines over each other. I typically convert most arcs and lines into polylines; the laser will typically cut a continuous polyline in one stroke. Also, you need to leave little breaks, say 1/8" or .1" for thinner balsa and perhaps half that for thicker stuff, periodically. If you don't when your sheet is picked up, all the parts will fall out. The builder should use a sharp exacto blade to free the parts.
These are just some general comments. Best to become very familiar with your CAD program (say by editing a drawing of interest) first, get competent with it, then talk to your laser cutter for general guidelines.
As for plans, I suggest that you look into emitting a full sized plan as a PDF. Most copy places can print a PDF full sized, and this is a good way to transport your drawing electronically. I have an older Version Acrobat Writer program which installs as a virtual printer, and my CAD program just prints a file to it, generating an output PDF. There are several freebie programs around which accomplish the same thing, I've heard several people mention them.
That's pretty much the bulk of my own model airplane CAD general knowledge.. I'm sure more professional CADers here will chime in with better and more specific information.
With great power, CAD packages require great training and experience.
Good luck!
L.
"There is a computer disease that anybody who works with computers knows about. It's a very serious disease and it interferes completely with the work. The trouble with computers is that you 'play' with them!" -Richard P. Feynman