We might have to agree to disagree on that, because I'm not clear why you think the person claiming to be Ballard is no longer her because she was given some alien biologies and cultural influences. The ep makes it pretty clear that most of her original human personality survived and that she still wanted to be on Voyager, but that her alterations also made that difficult. I don't think it's comparable to Tuvix at all. By your definition, Sisko wasn't human because the Prophets caused his birth and interacted with him on an exclusive level so he could be their emissary.
My issue with things such as Data and the EMH is, if we give everything man creates that behaves as we do equal rights, then where do we draw the line? When is a machine just a machine? How broad is the spectrum of what we consider "real" life? If we give Data and the EMH rights, then do ALL androids and Holograms get rights too? If so, then the holodeck can no longer be a place of entertainment, it now becomes a society and using them then becomes exploitation or denying rights of androids & holgrams then becomes discrimination, regardless if their abilities or awareness is limited. There has to be a defining line of what we see as life and what is a creation that is only meant to serve as a tool.
Are Data and the EMH property?
Are they owned by Starfleet?
I'm fairly sure the EMH is.
If he's considered property, then he has no entitlement to rights.
Data is a machine, is he property too?
These things are considered equal to those on the ships they serve on but how does society as a whole view them?
We see them as real thru the eyes of Picard and Janeway but what of those outside Starfleet? Would the regular person on the street view Data or the Doc. as life?
What of the races in the Federation that are religious?
Are Data and the EMH considered perversions if even considered given rights?
It's a valid question, and my own feeling is this: Data and Lore were always intended to have the capacity for sentience that humans have, in the same way that a planet full of Soong-type androids could be expected to develop their own culture and traditions. The Doctor and other holograms have that same potential too, but because they are designed primarily as tools or companions they're less likely to take the initiative on their own. The EMH did because of Voyager's unique situation, and I don't mean to infer that he's less sentient than Data as a result.
We tend to develop our own definitions of determining life and sentience, but as Picard pointed out in "Measure of a Man," Data met all of the perceived qualities for sentience that would also apply to a human. It's hard to judge how society as a whole perceives them, because we just haven't been given much information either way. I don't think the Bolian published was necessarily biased against holograms (I'd have to go back and watch the ep again), but he didn't feel bound to honor Doc's request because the law says that holograms don't have the same rights as others.