Thin hair? Get it cut and fluffed out a bit. Longer layers help to give it some fluff (unlike none or a short cut)/ If it's really bothering you, add a removable halo hairpiece.
Your nose balances out the rest of your face.
Your cheeks look make you look healthy and youthful and help balance the length of your face.
If people say you genuinely look young, it means you look healthy.
Small ears? Who cares? (said as somebody with a congenital deformity on one side that nobody has ever commented on in my entire life).
Flat chested? They won't look saggy and deflated, then.
Pale? Get a spray tan, then. Or sweep a bit of blusher across your cheeks and nose and the lightest shade of bronzer around the sides.
Moles all over arms? So what?
Short legs? Apart from it being a pain in the arse trying to get trousers to fit M&S I'm looking at you with your new so called short leg length here, as long as they reach the ground when you stand up, they're just the right length.
There's stuff you can do something about, there's stuff you can't and most of all, there's stuff that you're criticising that could easily be things that make you attractive or at worst, perfectly normal in the way that most people are distinctively themselves and not everybody else.