you can do a puppet bridge for your discord account so it bridges all the guilds your in to matrix without needing discord guild admins to add the bridge to it
did you host your own matrix homeserver or use matrix.org? that can change how fast it feels massively and yeah built in moderation tools are pretty much nonexistant https://github.com/the-draupnir-project/Draupnir is the only moderation bot that you can run to ban users from all rooms at once if they break your rules and lets you subscribe to banlists so if a user spams in other rooms that have write access and gets added they'll be banned from your rooms as well
cinny.in is much closer to discord then element
Depends which hard left, I know hard/far left people who hate them
Yeah that's one big hurdle to get past sadly, it's like getting people to switch to a new chat app "no ones on it I talk to so I'm not bothering"
thats google safety net which only allows apps that use that check to be installed on google verified OS's which graphene cant become