One main challenge was likely mobility. At 600 pounds, simple tasks like walking or standing for a while would have been difficult. Another could be her diet, changing from high - calorie, unhealthy foods to more nutritious options.
Ash might develop a deeper understanding of different training styles. Bianca has her own unique way of training Pokemon in the Unova region, and through their interactions, Ash could incorporate some of her ideas into his own training. Bianca, on the other hand, could become more adventurous. Ash's tales of his travels could inspire her to explore more areas in Unova and take on greater challenges. Their relationship could also lead to both of them becoming more empathetic towards others, as they support each other through various difficulties.
It's hard to say. You might need to check with the publisher or look for specific information about the comic's translation status. Sometimes, it could be available in multiple languages, but it varies.