In my opinion, they're quite good. They expand on Darth Maul's character and provide some intense action scenes. The writing and illustrations work well together to create an engaging experience.
Naruto would probably be very curious about Ahsoka's Jedi powers. He might constantly ask her to show him how her lightsaber works. Ahsoka, on the other hand, would be interested in Naruto's ninjutsu and his ability to use chakra in different ways. They would likely start off with a bit of friendly competition, showing off their skills to each other.
Well, determining Ahsoka's age in the novel can be a bit tricky. It often depends on the timeline and events of that particular story. Sometimes it's explicitly mentioned, but other times you might have to do some detective work within the narrative to figure it out.