3.X drivers don't have the problem, but they don't support VersaLink and AltaLink devices because 3.X stopped being developed before they launched. That does not in any way pose an issue to the C60-C70 models
4.X drivers don't support 32 bit applications, 32 bit applications have the Printer Features problem and will for as long as people use them.
As far as I know, Xerox never announced they would fix this, the statement from Apple was that in June they would stop supporting 32 bit applications, but they have increased that timeframe it would seem with the announcement that 10.14 will launch, and will support 32 bit, but now they will not just once display an error when you use one (ala 10.13), they will display that error that you should not use 32 bit applications every single time you use it (10.14).
As for MS Office apps, They work, early versions of Office 2016 were 32 bit, they all converted to 64 bit on version 15.25. And Office 2011 is no longer supported (By MS/Apple and Xerox). Office 2016 has the free update to 64bit
Safari is broken in a completely different way, as I have been told, the developers don't follow Apples own guidelines.
No idea on Pages, it didn't work late last year, there was an update to pages and it did work, the latest release no longer does, I have no idea why or what update caused it.
Of course for official answers from Xerox engineers and developers, you need to go through them by phone, I am just in the trenches and here un-officially, answering what I can, when I can, to the best of my ability. All my answers are from my experience (Working in the support trenches) and via 3rd party information passed down from up high (SPARS sent to Engineering and answered) and simple Google searches.