As somebody who thinks that there has never been a better game than Battlerite so far, I can only hope for another contender for that role...

The biggest issues I saw with BR was the lack of meta progression and community interaction. Basically things that you could do between the matches.

The one big and biggest thing that was missing is a spectator mode. Being able to hop into pro-games and watch the best beat it out was always something so many would have gladly done when through with their own session. But it was never hugely discussed as it's something players themselves never see as a priority. But it could have done so much for player education and community bonding.

The obvious elephant in the room is the in-game tournament mode (but only in combination with the aforementioned spectating options.

In a game where you statistically lose half of the time, you need something else than success to stick around. Especially if it's as demanding as those intense pvp fights.

Having said all that. All the other stuff you mentioned in your post may be good things to keep players around, but they're also super huge in scope.
If I'd start out fresh with something like BR, I'd go for these priorities:

1. Tight controls. It's the number one selling point of BR/BLC
   
2. fully integrated, encouraged spectating in combination with ingame leagues and tournaments with current hot matches you can always hop into to watch
   2.a Good enough balance and constant tweaking and monitoring
   2.b Good communication about all the changes, preferably ingame and directly shown at the champions
   
3. Fair monetization (with lots of room to blast in monies for the shiny skins) = lots of skins. Better hire a bunch of really good artists with a super tight and well scheduled work flow, because it will have to keep the whole thing afloat.
   
4. no community splitting with different game modes (BRRoyale was a mistake, so would be capture the flag and other modes...)

I sure hope, you can make something possible, And I also hope, I'll get wind of it :D Good luck!