Yesterday I caught an early Babylon 5 ep, which I could say more than one thing, but I'll just say this:
I believe Talia was initially intended for the arc given to Lyta (when they wrote Talia out of the show). I thought about it and even looked stuff up (though they're very discrete about behind the scenes, but they often were with other snags and problems they ran into--which I think is a good thing, at least more often than not, despite it frustrating my curiosity now), and I'm now convinced of this despite unable to find hard proof, just deductive reasoning.
There are just a few tweaks I can think of (which probably were in the original idea), but that what happened to Lyta was originally supposed to happen to Talia before the actress had to go (be it on behest of others or herself). And it flowed better as a story that linked the first and last season well for me, so sorry it didn't work out. (Not that I have anything against Lyta and enjoyed a novel featuring her with G'Kar, and it remains one of my favorite shows.)