OP wrote:
Who says we have to use one name at one time our entire lives? In many cultures today or in the past, it was common for people to have multiple names for various purposes or phases in their lives (pen names, honorific names, religious names, and names for coming of age, the death of a parent, etc.) I see no reason why using multiple names should be objectionable in anyway.
That's the deal here. Here I get called Teacher, Husband, Father, SistersHusband, OwenDaddy, IainDaddy,ShiShangMing,ShiXianSheng, ShuShu, even Uncle by kids whose parents think that's the correct way to address a white man, plus my actual first name. The given name part of my Chinese name? Never, never ever.
For some reason, given names are the norm at Academia Sinica. Anywhere else, it's a big no no.
English first names are used in Taiwan among people with no foreign connection whatsoever, who speak no English, or any other foreign language. This may be because they're not sure which of the other possibilities is PC, or perhaps they just want to seem cosmopolitan and cool. Either way, the Taiwanese are happy with loads of names.
In the UK, I only ever get called by my first name (or Daddy). No-one even calls me Mr Smith, although I suppose someone like a bank manager might.
In our case, like x3m, we thought one name per person was enough. 歐文 for Owen, 毅恩 for Iain. And my wife's surname, cos there ain't no Smith字 in Chinese!
Two surnames? With respect, that's well weird.