Prestel was the post office's varient.
I'm a big fan of ultra low bandwidth technologies. We need our own comms network - in order to access the forums and other services. The ones currently in use are not entirely trustable, and worse rely heavily on the goodwill of third parties.
Ofc, services additional to the forum are another topic to comms networks. For additional services I think it's wise to secitonalise, and not offer multiple choices for the same thing. Deploying an additional NNTP server would allow usenet-esque facilities, but then there's two places of active discussion - potentially for the same topic. Worse they are not actually intended from the ground up to be compatible.
Confer-U or Mystic BBS can be setup for deploying BBS services, but how many users actually remember them? It's increasing the attack surface for little reason, there's nothing that can do which the website couldn't, and much of the "features" to such a system are unrequired. Everything you list: access to databases, communication, message boards, etc should all be possible within the existing service. In most cases, it's incredibly trivial to achieve. Consolidation advantages make me think the current service should evolve into a portal - If it was me doing it I'd seriously consider use of something like chromium(the OS, not the browser. Yes, it's the same project) or EyeOS, but I'd minimally expect the likes of collobora(effectively puts Libre Office into a web site) - but just using Django it can revert to a kiosk interface wherin the user has a full on interface inside their browser, select which facet of the services they would like to play with and away they go. That can be done with some basic PHP... It could be built entirely on open source projects which should make it trivial to deploy and maintain, and if built in a modular fashion it means it's then trivial to embed one part into another, or swap out one part for another at a later date as time progresses and new needs must be met.