A tier 1 item that increases jump height and distance a small amount then two tier 3 items that use the same tier1 item. one for jump height and one for distance.
Yes.
I think this would be quite cool - some kind of mini majestic leap with a shorter CD might work too. Something that isnt a teleport, and isnt a huge height like majestic leap. Maybe a 1250 spirit item, to offer an alternative to Warp Stone and Fleetfoot
I'm not sure about this since it could easily lead to players getting into unintended positions rather quickly. I'm not one to discourage exploration and map use, but this could be a really obnoxious item with Lash, Vindicta, McGinnis, and so on.