sattvik
Thanks for the info on Khyatti. So she is the real MIL of Vishnu. I've seen 2 accounts of Lakshmi's parentage - in the samudra manthan, it was Varuna who presented her to Vishnu, which is why he is acknowledged as her father. But I've seen accounts where Bhrigu is Lakshmi's father. Any idea who Varuna's wife(s) was/were?
On your other point, Brahma is rarely worshipped, so if someone is exclusively worshipping Vishnu or Shiva, either is pretty legit. I've never seen a puja involving worship of both Vishnu and Shiva, since in that case, a question would have come up of why leave Brahma out of it, which would invoke the above story.
Varaali
You're right - Vinati & Kadru (mother of the dog species) are the other daughters. I think in the doubts & discussions in the Ramayan, in some context, this came up, and someone provided all the daughters of Daksha.
So aside from Rati, did any of Daksha's daughers marry devas or kshatriyas, as opposed to sages?