I never mentioned that Sheik was broken, just above the majority of the cast, although I could have worded that better.
Zelda on the other hand is pretty bleh to be honest. To my knowledge the only combo starters she has are Nair and D-tilt.(I would say D-throw, but that's only if the opponent has bad DI.)
Her kill power is amazing, but other than her Up-B, her only options for killing are Fair, Bair, Uair, and Back Throw. In regards to the three aerials, they suffer from being ridiculously hard to land and incredibly unsafe. Uair is terrible due to its startup lag, while Fair and Bair are not autocancellable from a short hop, which makes them unsafe to throw out at all unless the player knows they are going to sweetspot. Her projectiles are some of the worst in the game. Both Phantom Slash and Din's Fire is easily telegraphed and avoided without effort.
I could be wrong about any of these, I am not a Zelda main. I'd love to see me proven wrong because I want to have a Smash game where Zelda is finally good and viable.
EDIT:
Focus I do agree that Smash 4 is very well balanced. Arguably the best balanced Smash has ever been bar Project M.