1. No, they are not dating--they are only friends.
2. I don't think Vasilis's assigned gender at birth should be important. While I understand some people are just curious or are looking to find characters they relate to when it comes to one's gender experience, I prefer not to make a big show of what they were "born as" because it is often used as an excuse to misgender the character. Vasilis doesn't have a gender and only goes by they/them pronouns, thank you for understanding!