Alright, I stumbled on this one and it is much nicer to a GM to say "I have this trait" than "I'm playing a character with a disability, hiw do you want to handle it?"
So, concerning this trait. It's a religion trait, and the character will likely not be on that religious path. They were a con artist gambler, saved after an outraged mark caught on and took their Tiefling eyes as compensation. Eyes that can cast Deathwatch? Valuable on the black market.
So yeah, they're true neutral and self interested. No matter how thankful they are to their Vildelite saviours who helped her see the world again, she's still flawed. Relying more on luck from a deity like Desna than an Empyreal Lord of martyrs and self sacrifice (though I do like the moral conflict of not wanting to abandon new friends that accept her in the party).
So question 1: if you don't follow a deity anymore what happens to a religion trait?
The other part to this, is the character in question is a Wizard. In particular a Divination wizard, replacing her sight lost in arcane sight, with spells like detect magic, arcane eye etc. As well they aren't giving up Necromancy, which opens up the option to animate dead an Istoq which can share senses.
So question 2: since you lose the benefits of the feat whenever you can see, would it be lost if you were able to see the world through another's (or magic) senses?
I think the purpose of making it a religious trait is that the church of Vildeis took you in when you were blind and taught you how to get around. So you have a prior relationship with them and were at least able to fake it pretty well, but what you do when you're out is up to you. It's not like you're going to have your training removed if you anger a deity- it's training, not magic.
Being able to only have one religious trait is basically "you have only had time to be associated with one religion".
But as for "seeing out of magic senses" I would say that turns the trait off. It's "whenever you can see" not "whenever your eyes start working again."
Although I don't know of any specific rule for traits, the general rule is that if you don't meet the requirements for something, then it doesn't work. How you would explain that is up to you.
If you can see, it doesn't work. Now, whether or not those spells let you 'see' is questionable to say least. Nothing in those spells allows you to remove any of the penalties from blindness. Arcane sight in particular would be troubling, as you have to be able to see to create the sensor.
The big thing though is the the rules as written really don't deal well with blind characters, that religion trait not withstanding, and especially don't deal well with how other typically visual based effects (detect magic working based on line of sight for example) work when you are blind. You are going to have to make sure the you and the GM are on the same page for all of that.