Most changes I want are honestly just UI-related.
1: New selection order is Rules -> Characters -> Stages
I like having stages before fighters in theory, as it allows for some strategic decision. Buuuut in practice it honestly just feels backwards, and actually completely screws up some of the flow of other menus. For example, you can't change rules from the CSS without being forced to re-select your stage. And CSS is just a more natural place to immediately appear after a battle due to containing options like names, rule changes, and setting up the amount of players etc. Besides, people playing seriously more often than not prefer to stick to an extremely small pool of fighters anyway, so the fighter decision is not that relevant, as they will always have a character they're waaaaaaay more skilled with as opposed to one that'll fit the stage. People also complain that they're forced to reselect characters after every fight. This is the reason. They're expecting you to select a new character to better fit the new stage. But most people just don't want to do that. Seriously, the new selection order just brings way more problems than it solves.
2: Rules can be adjusted without selecting or saving a ruleset.
Here's how I think it should work. Get into the Smash mode, you get a list of your saved rulesets. You can manage rulesets from this menu, it's all good. It's identical to how it works right now. Awesome.
But once you reach the CSS, **** changes. Click the rules icon, and you're not thrown to the ruleset list, but directly to rule settings. The rules in the settings are from the ruleset you selected, but if you modify these rules, they will not be saved to the ruleset unless you specifically do it yourself. The current system is stupidly annoying, as every time you want to make the tiniest of changes to the rules, you have to mess with rulesets, save everything, and even freaking reselect your stage and character before you're back in the CSS exactly as you were. This is the case even if you want to change the amount of lives of the match, which is a freaking humongous step backwards to how **** worked even back in Smash 64. They had this figured out, and the ruleset is a ridiculously amazing addition that should've been here long ago. But the implementation was just terrible, and just made rules way more annoying to navigate.
3: ****ty controller/menu shaenanigans.
This thing was just plain changed for the worse. Now, you can add and remove portraits with the buttons on the right of the screen. Good right?
Bleh. You can only remove the player who joined last. If you are the player who joined last, you can only remove yourself. You can't turn other players into CPUs. And hell, if a player stops playing in the results screen, you can't even proceed to the next screen unless you pick up their controller and press A.
This just generally sucks a lot if you're just playing casually and you're the only one who understands how menus freaking work. The way this whole system works is just freaking awful if you play with several people who come and go all the time. Like, you have five friends playing, but three of them leave to do something else on the results screen? You have to pick their controllers one by one to confirm that they're all "ready" to go to the next battle. Good luck if you have like 12 controllers sitting in the room. Just... Why is this a thing? You should be able to deactivate any player and turn them into CPU or whatever. And you should be able to leave the results screen from an 8 player match with just one controller. There's too many annoyances here.
4: I want 4 player Squad Strike. Just want to use multiple characters in a regular battle. It's a great mode as it is, but way too limited. It really needs to support more players.
5: A+Jump=Short-hop attack as an option. I don't need this. I don't use this. But I do use it on accident, and it takes away my ability to buffer an aerial out of a full jump's squat.
That's it. Everything's relatively minor, but it affects my experience way more than it should.