Any sort of Dalish Inquisitor would lack the orthodox beliefs of regular Dalish. Merrill is another example of a Dalish elf that doesn't adhere to the Dalish orthodoxy.
I don't think the Dalish Inquisitor would necessarily lack the capacity to be an orthodox member of the People. I agree that Merrill is unorthodox, but that's because she's a blood mage; she actually shares the same orthodox views as the Dalish about the elven pantheon, magic as a gift of the Creators, viewing spirits as dangerous. If you meant it because of Merrill's view of the elves in the Alienage or her perception of humans, I don't take Merrill's view that the Kirkwall elves are still elves, and not having a problem with humans, as signs that she's unorthodox.
Will there be a schism in the Dalish community sometime soon? I hope so. It's time to get over what happened centuries and centuries ago and work to build a better future for elven kind. The Dalish aren't very constructive in this approach living as a clan of bitter, racist nomads roaming the countryside feeling sorry for themselves. The more Dalish decide that what they're doing isn't working, the better.
There are variances with the clans already, as Gaider commented on as far back as the old Dragon Central board, when he mentioned all clans have their differences (with the exception of commonalities, like the view of the Creators, the prohibition against using magic that involves spirits, and issues like that). However, the Dalish way of life is more about survival than building towards a future; that might change if the prospect of a homeland is available as a path for the elven Inquisitor, but otherwise, I don't see that changing. It's not like the Dalish can live side by side with Andrastian humans when their religion has been outlawed, or who would expect them to give up their culture and religion.
A pan-elven future where the Dalish can work with and live with the Andrastian and Qunari elves in a permanent settlement would be very interesting to pursue, at least in my opinion.