"The ability to add nicknames/maiden names etc is of no use to people who actually need to keep their identity secret for their own or their family's safety."
"There are plenty of perfectly legitimate reasons for someone to need, not just want, to use pseudonym."
I'm sorry, but you don't need to use Google+. And for the love of Peter please don't if you'll endanger yourself or your family.
Wanting to remain anonymous on Google+ is like going to a dinner party and insisting on wearing a mask. Yes, you'll reduce the chance that people will know who you are—but you're also super freakin' creepy. If you don't want to be recognized...stay home or go to another party!
And if you don't want to share your real identity online, I'd recommend not using social networks altogether.