It's just a matter of adjusting the transparency of the lines. Go to Settings --> Print and Paper Settings and move the transparency slider to 0%. For the edge numbers, go to 2D Menu and click on Show Edge ID.
Stick with #110. This is more than sufficient for making armor pieces. Besides, most printers can handle this weight. Heavier weights require that you feed them to the printer differently, depending on your printer, which can be time-consuming.
Nothing. I clicked on the zip file, chose where to put the extracted folder, WinRAR flashed the error messages but extracted the folder anyway. Only one file turned out bad or unrecognizable by any program.
I fiddled around the zip file and here's a few things I found:
I was able to open the file and extract the folder despite the syntax error messages.
All but one of the pdo file can be opened. It's the foam file that is bad.
The foam file probably came originally from the therpf.com site...
The latest version of PD4 (4.0.1) should be able to handle all pdo files, including PD2. Since you mentioned that you're having issues printing the lines, go to Setting --> Print and Paper Settings and move the slider to 0% transparency. This should resolve your printing issues.