One risk could be harassment. Strangers might make unwanted advances or comments. Another risk is the potential for theft if the stranger has bad intentions and sees an opportunity.
The hero has become a stranger, the beauty has become old. This was a classic novel description that meant that a former hero or beauty had reached the end of her life or had gradually aged with the passage of time, becoming no longer beautiful or powerful. This sentence was often used to express that the fate of a character was affected by time, and even the glory or charm of the past could not be maintained forever.
Wives can use anonymity. By not revealing their real identities, they can share stories without the risk of being directly identified. For example, using a pseudonym in online forums.
He can be calm and positive. For example, he could join in the fun and dance with others too. This shows that he trusts his wife and is also confident in himself.
The story doesn't fully reveal who they are in a very straightforward way. They seem to be outsiders with their own motives and secrets. One might be a criminal on the run, another could be a wanderer, and the third has some sort of connection to the first two, but it's all left quite ambiguous.
One potential risk is privacy invasion. Her personal details might be misused. Also, she could be vulnerable to manipulation as strangers may not have her best interests at heart. There's a risk of her getting into unwanted arguments if the strangers have different views.
If you feel uncomfortable, it's okay to gently end the conversation. You could say something like 'I'm really sorry, but I have to go now. It was nice talking to you'. However, if you're okay with it, keep listening and try to make the experience positive for both of you. For example, you can share a relevant but brief experience of your own to show that you can relate to them on some level.