We are having the same margin issue with the 30-label sheets as well.  Someone should merge this with idea K12OR-I-636

I am having the same issue with mailing label exports to Word - margins too large and font size adjustment issues. It's hugely frustrating and really negates the mailing label feature as it's pretty much useless. Creating a mail merge has been more effective, although not optimal, but better than the mailing label option. 

There is also a problem when the labels are to be exported to Word. The export gives too large of a margin around each label (at least for the quantity=30) and doesn't allow you to increase the font size without text being cut off.

Agreed!!  The point of a mailing label should be to be able to properly print a mailing label!