While the effects of a rhinoplasty, chin augmentation and fat removal from the neck would be very beneficial for your facial thinning goals, the thickness of the chubby cheeks is not so easily improvable. Botox is to slim down the muscle over the jaw angles. Buccal lipectomies would be more effective for the cheek area.
You should stop at liposuction of neck. I recommend against rest of your plan. It is best to have a consultation with a professional to understand these issues as they apply yoy.
Neck liposuction, rhinoplasty and chin implant candidate
Liposuction can accomplish removal of fatty deposits in the neck, as long as you are at your ideal body weight and those fatty deposits are diet-resistant deposits. the bridge of the nose can be built up with patient's own cartilage and height along with narrowing the bridgeline.A chin implant and inserted through a submental approach to give added projection to the chin to help with facial balance and proportions. Performing a chin implant is complementary to the neck liposuction to give a better jawline. Chin implants manufactured in a large variety of shapes and sizes which is best determined at the time of the consultation and examination. For more information many examples of all 3 procedures, please see the link and the video below