Sorry to take so long, I'm still not used to getting feedback.
Having multiple bindings for the same key is intentional, in case someone wants multiple functions per key-- several times I've been frustrated at a game preventing that and requiring me to memorize more keys.
The climb function will be more useful in the final game.
Jumps don't kill your momentum, they preserve it. If you are holding a direction when you press jump you'll jump in that direction. The trick is you can't change direction in the air, so you have to plan your jumps. It's not too hard to jump to the floating platform.
That's a good idea about the attack ability. The standard attack will have more verticality in the final game, but I may use that idea anyway.
Thank you for your feedback.