I know that the shows creator (and writer of most of the episodes) never wanted there to be a "Babylon 6" and his only intended continuation of the show was "Crusade". But I would like to see something aboard one of the Babylon stations themselves. Lots of background to explore there. We know the history of Babylon Five of course. And the fate of Babylon Four was shown during the series. Sent back through time to serve as a base in the last war against the Shadows. We know that the original Babylon station (later called Babylon One) was destroyed in a superstructure collapse near the end of its construction (sabotage) We know that Babylon Three blew up near the end of its construction (sabotage). But other than it was destroyed in some way (sabotage) we know nothing whatsoever about Babylon Two. More than one official source suggests the completed Babylon 5 was smaller (and cheaper) than the previous four stations. Babylon Two had to have been under construction for years before it was destroyed. Years of worthwhile stories to tell and adventures to explore.
I thought Crusade was interesting though the changes that the network insisted on after production had already started meant some jarring transitions. I've always wondered how the extended story was going to play out but I've heard only bits and pieces. All I heard for sure was that during the 2nd season the cure to the Drakh plague was going to be discovered but it wasn't going to be the kind of "cure" that people (viewers or the people in universe) expected. And that subsequent to that the crew of Excalibur was going to have to go on the run from Earthforce for some reason. Eventually Captain Gideon would die a terrible death because that is what happens to everyone who possesses the Apocalypse Box.
Crusade had an interesting premise, but it's execution could not have been worse. Babylon 5 was very complex and dramatic, packed with complex lore while still finding time for humor. Crusade might as well have been a cartoon in comparison. It wasn't even the most interesting event B5 was leading up to. I was far more interested in the telepath war, watching Mr Garibaldi fund his sweet revenge against Bester.
l Rumors were that J. M. S. was told to "save" the Telepath War storyline for a potential Babylon Five movie. Remember that though J.M.S. created Babylon Five and wrote the majority of the episodes, the series still did not actually belong to him. The studio had (and has) all the rights to it.
Crusade's hook was going to be, like you said, the cure happens in S2, but then Gideon finds out that Earth politicians were in on the whole thing for whatever evil reasons, and he has to take the Excalibur on the run to stay alive and possibly reveal the truth. The mess it became was entirely the fault of TNT network suits. It was jms's worst experience with network interference ever. It's said that it was clear the network didn't want the show, was trying to kill it from the start, and went out of their way to screw it up. The reason the show aired out of order was that, after 6 episodes were filmed, the network demanded a new action-packed pilot (with fist fights! People like fist fights!), and demanded better-looking uniforms. So jms wrote what became the new first episode, with a fist fight and new uniforms.
