Your backstory sounds completely reasonable to me. I can definitely see a miqo'te tribe that's very into its religion banishing those who speak out against it. I can also see a tribe that wants to adopt someone insisting that they prove themselves, especially with what I see as the miqo'te's constant drive for personal superiority. It's also reasonable for a Seeker male who's no longer part of a tribe to change his name; it's not like names are permanently fixed, after all. 
You may want consider why he'd change his name -- is he opposed to tribal culture? Feels he doesn't deserve the name because he was forced out or left on his own because he felt unworthy? Decided he was something more or better than what the name "tia" represented? There's an interesting spot to add to your backstory and personality there.
All in all, I'd say you're in a fine spot. You have an explanation for why your name doesn't meet naming conventions, and everything else fits within lore, IMO.
As a side note -- and bearing in mind that I'm not calling anyone out or saying they're wrong -- as interesting as those threads on mating strategies and dominance challenges are, they're speculative "fanon" and, while they can explain some of the lore, are not themselves lore, nor do they represent any form of community "consensus" (nor would or should any such consensus have any authority over you). You can feel free to use all, none, or some of what Callipygian and others wrote in those threads based on whether it works for your character. As I said on another thread, just because some Seeker players agree with the arguments presented in those threads doesn't mean you have to; no one has a monopoly on truth except for the devs.
EDIT: Right, what Ildur said. *points below* I missed that on my first read of your post. "Very few nunh ever become leaders." (dev post, Miqo'te Naming Conventions)
You may want consider why he'd change his name -- is he opposed to tribal culture? Feels he doesn't deserve the name because he was forced out or left on his own because he felt unworthy? Decided he was something more or better than what the name "tia" represented? There's an interesting spot to add to your backstory and personality there.
All in all, I'd say you're in a fine spot. You have an explanation for why your name doesn't meet naming conventions, and everything else fits within lore, IMO.
As a side note -- and bearing in mind that I'm not calling anyone out or saying they're wrong -- as interesting as those threads on mating strategies and dominance challenges are, they're speculative "fanon" and, while they can explain some of the lore, are not themselves lore, nor do they represent any form of community "consensus" (nor would or should any such consensus have any authority over you). You can feel free to use all, none, or some of what Callipygian and others wrote in those threads based on whether it works for your character. As I said on another thread, just because some Seeker players agree with the arguments presented in those threads doesn't mean you have to; no one has a monopoly on truth except for the devs.
EDIT: Right, what Ildur said. *points below* I missed that on my first read of your post. "Very few nunh ever become leaders." (dev post, Miqo'te Naming Conventions)
The Freelance Wizard
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
Quality RP at low, low prices!
((about me | about L'yhta Mahre | L'yhta's desk | about Mysterium, the Ivory Tower: a heavy RP society of mages))
