I do admire that you lot are trying really hard to make this work, as it seems the majority of the competitive community has simply agreed that since one character has an enviable followup, the game is "slow and lifeless". Pretty much the initial reaction to Mario Kart 8, if I remember correctly. Also that Equipment and custom moves should be ignored as "it takes too long for TO's to do that stuff" and "you obviously mean +199 speed, so no". I've found that mii's have been banned on occasion simply because TO's don't know the match up.
But, overly convenient as it might be, I don't think that heavy gravity will work in the long run as an element for a fast paced game-formula. It will kill certain recoveries, and even if you give characters improved jumps by speed boosts or effects, you can already see cracks in heavy gravity/S landings effects; Ganon/Falcon dair infinite was found pretty quickly. Also, it initiates fast-fall the second you start falling, which is not a very good thing for characters like Falcon, Ganon, Shulk etc.
However, I'm not saying that this is useless, or that it should be abandoned - but to me it's looking to be more limiting than liberating.
I've said this in a few other threads (hell, it's why I signed up), that there's an equipment effect called 'Anchor jump', which kills your falling speed by about x1.4. I have compared this to falling speed in melee and 64 by using the maximum height Fox can achieve by double jump + Fire Fox, then recording their falling speed. You can find an identical set of data for all characters on antd.org, although its only Melee data so far as I know. To conclude, I found that multiplying Fox's falling speed by 1.4 still didn't bring it close to Melee, but that it probably wouldn't send him slamming down the second he falls.
While 64's falling speed didn't really help, I found an odd effect that imitates the game's slow, wavering fall animations in 'Thistle Jump' (x0.6 falling speed), which might be something to note. You can find all of their falling speeds on Youtube from an account called 'William5000000'.
That said, my ideal formula includes (but not limited to): A balancing selection of Smooth Landing*, Dodgy Dodger* and Anchor Jump.**
*Tested, worked fine.
**Untested, still grinding for it.