The countries that have converted to SI are the countries that were late to the industrial revolution party.

Are you suggesting that Germany, Britain, France were late to industrial revolution party?
By the way, metric system was established during France revolution, just couple decades after the US Declaration of Independence. Plenty of time to come on board, right?

For everything graphical like 2D/3D plots, complex drawings and even solid-body shapes in PDF format I would recommend "Asymptote: The Vector Graphics Language"
http://asymptote.sourceforge.net/. After some learning curve (it is a full-blown interpreted programming language) I never looked back on anything else.
Asymptote is GPL software and comes with good manual and tons of examples in the Internet.

Germany has reasonably strong consumer protection laws.
She can "return" her merchandise to the seller for "full refund".
In this case it amounts to unistalling the OpenOffice, deleting the installer, might be even taking a screen-shot of the message showing "uninstall complete" and send a polite and firm message to the scammers (optional).