Your real problems arise with an unmediated forum (which Twitter is) when someone uses it anonymously to harass or bully someone they name.
I would set up a basic website that allowed people to comment easily but where the comments were only published after they had been read by a moderator (as they are here).
That only requires a box to be ticked in the back end of the platform (WordPress). You could even provide a password for residents only, to help cut down on spam and avoid complaints about airing your dirty linen in public.
I’m thinking of doing the same in my building where the committee has already started trawling for proxy votes in an effort to subvert the new anti proxy farming laws.
Most domain name sellers and service providers will give you a basic website for not much money