I approve of this topic.
But what about keeping momentum from dashing into jumps, because that appears to be absent as well. It would help a lot of the faster characters, like Falcon, Fox, and Sonic approach, gives more mobility, and I don't really see either casual or competitive hurting from it being in the game.
I think the momentum retention is vital and iconic to how some fast characters play and support this. (EDIT: Not to mention, it makes the game play "smoother" and less clunkier.) However, I will say when I played Melee as a kid, Falcon would turn me off so much because I would dash and run, and he would be half way around the world and got himself killed. It didn't irk me to the point that I hated the game, I mean, I loved the game, but casuals can be turned off by it. Now by no means every character must cater toward slow fingered casuals; diversity of style in the characters is important whether it is a for-fun party game or a competitive one.
As for suggestions (Most are already stated, but repeated suggestions should accentuate the importance of them.
-Dash dancing needs to come back, it's such a good tool to have and casuals by no means have to use it.
-Consider directional airdodge.
We're not going to get this one. If we do, there will be landing lag, so WD will be out no matter what.
-Buff SDI. It improves interactivity between players. Also help casuals feel in control even when receiving hits.
-I don't see a problem with throws. A lot of fighting games have throws be the
damage dealers rather than combo starters. The role of it can be anything as long as it's useful. What is important is that we can overall have a healthy combo game.
-Readjust blast zones.
-Nerf recoveries. Having KO's only be the ones where the characters are careening to the left, top, and right blastzones at 300 miles per hour reduces a dynamic of the game in which players can win by tactically outsmarting their opponents, something any player can appreciate and feel proud of if they can pull it off.
-Reduce landing lag. (Important one)
-C-stick should differentiate itself from a normal smash input by not be allowed to charge the smash. C-stick aerials should also not alter character momentum or act as directional inputs, but solely to use the aerial move, so a retreating fair shouldn't allow you to decelerate backwards because "forward" was pressed, or accidentally cause unwanted fast-falling. These things make the game deeper, makes the c-stick different from the regular inputs and are subtle enough that casuals aren't effected.
If anything, casuals love c-stick spamming, to the point of a lot of them calling it cheap.
Can't think of more at the moment.