I'm still curious about the rumors regarding Kal'tsit is actually Doctor's ex/current spouse/wife
So far I didn't find any proof about that, only got some info that they used to work together at Rhodes before Doctor got amnesia
Was it true or just a fan theory?
There's nothing whatsoever saying they were ever in a relationship as of right now. They did work together, that much is sure, and it's pretty obvious even from the very beginning of the game.
A lot of the Kal'tsit shipping comes from when she was playable during the beta, it was stated that Amiya and the Doctor were the two most important people to her, but it was left vague as to how they were important to her.