But the Ballard case shows her to be inconsistent with her principle of the original life form taking precidence. Until you're familiar with that situation, you can't properly judge Janeway on this issue.
Inconsistent in what way? It was Ballard's choice to ultimately return with the Kobali, not Janeway's, and the captain accepted her right to do so, as did Kim and her fellow crewmates (even if none of them liked the idea). It's not the same as the case with Tuvix in my view, because there Janeway did make a choice for him that nobody else could make.
They're both machines
Machines don't have rights.
Even "Measure of Man" & "Author Author" ends with that decision left unanswered because mankind still can't determine that they qualify.
Not sure I'd agree with you there. We know that Picard apparently played a significant role in defining rights for beings like Data in the Federation, and even Maddox seemed to quickly realize how difficult it would be to prove his original argument (Data didn't qualify for such rights because he wasn't sentient, but Picard demonstrated how hard it can be to define "sentience" for such a purpose).
"Author, Author" is a somewhat different case, in that holograms (who are usually designed to fulfill a specific utility or function) lack such rights under most circumstances, but I do think the Doctor would be a good case for potentially changing such laws. I'd consider him sentient by the time Voyager returned home, but he only gained that degree of development because of the Caretaker marooning the ship in the DQ, and only broke out of his "original" programming fairly slowly.