Don't you guys think Kalista is a little.....rushed?

The ultimate is entirely unique, the passive is entirely unique, the ghosts are entirely unique. The only thing not unique is that her skillshot is also a spear like Nidalee...but seriously? It's just the shape of it. If they made it look like a ball or a swirl or something you wouldn't think of nidalee at all, but the spell would not be any different. And Rend's active is like Twitch, but it's also unique in that it stacks infinitely, is not a poison dot, isn't spread by another AoE spell, and slows when activated.

Nearly every ability in the game is similar to another. It's meaningless to point them out.

I don't think it's rushed I think she just doesn't have as unique of a kit as we're used to. It's a real playmaker kit, she'll be a lot of fun to play, but as you pointed out her mechanics aren't terribly new, except her ult.

On the brightside it will be impossible for her release to go worse than Azir's

Kalista is the 122nd champion....They are going to have to reuse SOME themes. It all seems pretty unique to me, and each of the abilities you compared have different advantages and disadvantages and play styles.