The number of Futurama comic issues can vary. It depends on the release schedule and production decisions. You could try searching online comic forums or fan communities for more specific details.
One of the special aspects of Futurama Xmas Story is how it plays with the relationships between the characters during the Christmas time. It shows a different side of Fry, Bender, and Leela. Fry might be longing for the Christmas he knew in the past, Bender could be his usual selfish self but still get caught up in the holiday mood, and Leela might be trying to understand and adapt to this strange future Christmas. This exploration of character dynamics in a holiday setting is what makes it really special.
Bender might tell the best ghost stories in Futurama. He can add his own robotic twists and dark humor to the tales, making them both spooky and hilarious.
In Futurama, there's a story arc where Fry seems to be haunted by the ghost of his past self. This is a rather complex and interesting ghost story. Fry starts experiencing strange events and memories that don't seem to be his own. As the story unfolds, it turns out that it's all due to a time - travel related glitch. The show plays with the idea of the 'ghost' as a manifestation of Fry's unresolved past, which is a really cool concept.
The significance could be purely for comical effect. Maybe the writer thought it would be funny to pair a strange character like Clamps with a random object like a mousepad in a yaoi relationship.