The saggy skin in front of a cat’s legs is an evolutionary feature, not a sign of an out of shape cat.
The primordial pouch is the formal name for the saggy belly cats have. Some breeds have a more prominent pouch than others, but from big cats to house cats they all have it. It’s a loose flap of skin & fat which is the result of evolution and not the because of spaying or neutering (again, big cats such as lions and tigers have it too and they aren’t spayed or neutered).
One use for this extra belly skin is abdominal protection from the rear paw kicks of other cats. Another benefit is it gives cats greater flexibility (especially when they sprint or jump). It is also theorized that when early cats would find a meal this skin would stretch to allow the belly to expand and hold more food.
Pure white cats only make up about 5% of the overall cat population. Of these white cats however, 72% are deaf. In cat genetics, the gene that gives a pure white cat its white fur is also linked to the development of its ears and eyes. This is especially important for white cats with blue eyes.
This is only true of pure white cats, those with entirely white fur. Cat’s that are mostly white but have colored markings, pointed patterns, etc. don’t count as being pure white cats and there is no connection between their eye color and their hearing. Siamese cats for instance are mostly white but they aren’t pure white cats and so there is no genetic relationship between their blue eyes and their hearing.
Added info: Interesting side fact, the pigmentation in the coat of Siamese cat is heat sensitive and changes color based on the temperature. The colder parts of their bodies (their extremities: feet, ears, nose, tail) are usually darker while the warmer parts of their bodies are lighter. If you send a Siamese cat outside in the cold winter months they will get darker, and upon returning to a warm house they will get lighter.
Also, in the 1970 Disney film The Aristocats the mother cat Duchess and her kitten daughter Marie beat the odds and are both white cats, with blue eyes, but normal hearing.