Off the top of my head, here's my list:

>Purge and replacement of the mods
This is probably the main one. Almost all of the current moderation are either incompetent or actively despises the userbase. just look at how they literally refuse to enforce rules on this board alone with the constant flamewar and tech support shit. This site will never improve if you leave these people in charge. I would keep some of the older mods on places like /a/ and a few other boards around but thats it. Of course finding new people suitable to moderate might be a challenge
>Ban of e-celeb shit
Anyone suggesting an e-celeb board is a fucking moron, having some retarded weewee farms gossip space would be a /pol/ tier mistake and would just attract even more subhumans here
>sharty / frog / wojak shit is a bannable offense
>social media screencap threads are a bannable offense
>ban of culture warism /pol/tardism, politics (unless relevant) and retarded buzzwords
all three of these are pretty self explanatory, also rules against shit like 'redpill me on x' or 'about to play this game/show/anime, wat am i in for XD' being constantly spammed to force discussion should be better enforced


also a few quality of life things that arent neccessary but would be good:

>rangebans
israel and especially south americans would be good candidates. I remember the catbox admin was talking about how he had to ban brazilians as they were literally the highest number of non-VPN CP spammers
>Depreciate vp8, h264, AAC and vorbis, add AV1 and eventually JXL when it gets browser support
webp and avif can fuck off, anyone asking for it is a retard
>Raise the video length limit on boards like /wsg/
Useful for music threads
>New meta board
you'd need staff who actually listen to the userbase instead of erping in discord though

i think i missed some stuff but that's about it