Question regarding ancestors

Hello,

I'm sorry if this has been asked before, I searched for it but couldn't find anything. Also please correct me if I'm wrong.

I've recently read that (for the lack of a better word) ancestry work is a thing in Hellenic Polytheism. I will definitely do some more research on it, but I have a few questions about it that maybe someone here can answer.

My family situation is a bit complicated, so I’ll try to explain it as clearly as I can:

1. About the grandparents on my father's side. So my parents separated when I was a baby, and we have no contact with my dad anymore, but I really liked the grandparents I had from his side. Due to some family drama caused by my other grandmother, we have had no contact for years, though, and I am not certain that they are dead and have no way of finding out. Based on their age, however, they most likely are, so I would really like to include them. Is it okay to include them even if there’s a minor chance they’re still alive?
2. Now my other set of grandparents from my mom's side. My grandmother (mentioned above) was the worst grandmother you can imagine. While as a child I didn't notice it, once I grew older it became more evident; she was greedy, a liar, selfish, scheming… I could go on for a while. She did some pretty nasty things, and while, some time after she died, I tried to forgive her, so far I found myself unable to do so. Do I still have to include her?
3. Her husband on the other side was the complete opposite, and I was really close with him; he is, however, not related to me since he is my mom's stepdad. Can I include him even though we're not blood-related?
4. Now lastly, what about pets? I know they are not exactly ancestry, but many people count them as part of the family, and sadly, over the years, there have been a few pets I've lost.