kubok

You could look into Group-Office. Their community edition is open source and free. Looking a your list, it ticks all the boxes. It is also in active development; the Docker image is updated almost weekly.

Atheist here, married to another atheiest. If I were to date, beliefs would be fine as long as we were somewhat compatible. Open mindedness is a big thing here. Observing certain rituals would be no problem as long as I would not have to participate. However, if you are overly dogmatic or bigoted towards other people based on color, religion or sexuality, you can fuck off right away.