Perhaps it’s because I have a boy the same age, but I sincerely pity him. So young and he has kingship hanging over him with very limited ability to choose for himself. Entering an age where the world starts to open for his friends (and siblings to a certain degree) his will only close more and more. Poor kid.
He looks like a happy one though which is the most important thing.
I think he has a few more disadvantages:
(a) Frodo and Mares: Frodo is clearly not keen to become king and might have him "helping out" at a fairly young age. So a lot of pressure there. Mares will enjoy being Queen till her last breath. So whoever he will marry, she will have a hard time.
(b) The times ... our modern times and royality clash more and more. You have to be a very clever king doing outstanding work that people think "well, it is dated, but he is doing a great job...".