Question about effect commands

Hi! I'm currently building world that's made around the concept of a lunar base/outpost. The command (/effect @a jump_boost 1000 1) works very well at simulating how easy it is to jump on the moon, but I've found that the effect slow_falling 1 is a little overkill. Is there a command that can allow me to fall a little bit faster, like say slow_fallling 0.5? I feel it would work fine without the slow falling, but I want it to be as accurate as possible. Also, can you please add an attributes/itemData command that allows us to give an item a buff that is applied upon use, like say slow falling boots or a stick that gives us speed when right clicked? (sorry if I accidentally double spaced anything, my keyboard has been malfunctioning for the last couple of weeks)