Use lemmy.ml how you want to use it, and if you want to participate in other political leanings, go to a different instance. No one is really stopping you, and that’s the whole idea of the fediverse. And there really isn’t any value lost, because this isn’t a “choose one and only one” situation. You’ve got all of the fediverse at your fingertips.
Until you make the mistake of replying with the wrong kind of comment to the wrong sub, and get banned from the entire instance and lose the ability to post on many of the largest subs on this side of the fediverse. Or maybe they just see you out and about and decide to ban you on sight because they don’t like what you said. There’s nothing stopping that.
Admin overreach and abuse is a major issue for the fediverse because it affects more than just the user in question. Admins of large instances get to decide who has access to the users and communities on their instances, and very often the users of the instance aren’t even aware of the actions taken on their behalf. Mastodon recently implemented a notification for when blocks and defederation remove your follows or followers, and this is a great first step. Users deserve to know when they are impacted by decisions such as these.
I love the fediverse and want to see it thrive, so we need to stop putting our heads in the sand on this issue. It’s always discussed as if it’s an issue with a few problematic instances rather than the systemic issue in need of a solution that is is. Admins need the tools to protect their instances from real abuse, but we need to balance that with the right of the users to know what’s going on and not be unfairly deprived of the social aspect of this social media experiment, especially without knowing.
Something you might want to look into is using mTLS, or client certificate authentication, on any external facing services that aren’t intended for anybody but yourself or close friends/family. Basically, it means nobody can even connect to your server without having a certificate that was pre-generated by you. On the server end, you just create the certificate, and on the client end, you install it to the device and select it when asked.
The viability of this depends on what applications you use, as support for it must be implemented by its developers. For anything only accessed via web browser, it’s perfect. All web browsers (except Firefox on mobile…) can handle mTLS certs. Lots of Android apps also support it. I use it for Nextcloud on Android (so Files, Tasks, Notes, Photos, RSS, and DAVx5 apps all work) and support works across the board there. It also works for Home Assistant and Gotify apps. It looks like Immich does indeed support it too. In my configuration, I only require it on external connections by having 443 on the router be forwarded to 444 on the server, so I can apply different settings easily without having to do any filtering.
As far as security and privacy goes, mTLS is virtually impenetrable so long as you protect the certificate and configure the proxy correctly, and similar in concept to using Wireguard. Nearly everything I publicly expose is protected via mTLS, with very rare exceptions like Navidrome due to lack of support in subsonic clients, and a couple other things that I actually want to be universally reachable.