Worst Case Scenario of Rhinoplasty on a Young Patient?

The decision depends upon many factors. Chronological age, developmental age, type of correction desired, and current size of your nose. Rhinoplasty has been done as young as 14. However. if there is any question, it is always worth waiting until age 15 or 16 in a female patient.
The concern is that the surgery will disturb growth centers in the septum and outer nasal structures.

If you do not have functional breathing problems or a crooked nose, then the septum should not be an issue.
Most patients seeking rhinoplasty have a nose that they feel is too big for their face. In that context, interfering with growth centers tends not to be an issue of concern.

One additional piece of advice for you: If the shape of your face is not quite set, then you should choose a surgical plan in which the nose is left a little bigger. That way, when your face develops into its true adult size, the nose will balance well.

Typically, it is advisable to wait to perform a rhinoplasty on a male patient when he reaches the age of 16 and a female at 15. However, I would wait longer if you are a tall person or projected to be tall. The best nose is one that fits the face. Operating on a nose before you complete your physical growth could result in a nose that will not proportionately grow with you since it could affect the growth of the underlying cartilage and bone. For example, if you are 6 ft 5 inches, then a short nose would not fit your face. However, once you stop growing or are close to that point then a rhinoplasty can be performed.

The earliest age to perform rhinoplasty is 14. At that age, the majority of the nasal growth has occurred. It is considered "safe" to perform rhinoplasty at that age. However, unless there is major deformity, I prefer waiting until at least 16 to 18, given the potential interference with nasal growth centers. In cases of elective cosmetic surgery, you need to minimize your risk as much as possible.

The worst risk is the WORST RISK (and you know what that means). However, the feared common risk is interference with the growth center of the nose. Operating prior to completion of nasal skeletal growth means that you may prevent skeletal maturity or the opposite (the nose may continue to grow.

It is just not advisable to find a surgeon that will operate on your nose if you are less than 16 years of age. It is just not a good idea. Both cartilage and bone is not completely grown, and the rhinoplasty may arrest the development of the cartilage and bone of the nose. Please wait until age 16.