At the very least, someone should remember “Nobody returns from Z’ha’dum” isn’t entirely true – Nobody returns without being best buddies with the Shadows, maybe.

I think I'll add something to my fanon, to wit, Franklin checking Sheridan for implants and implant scars, and Lyta scanning him after he volunteers for that to prove he's neither been lobotomized a la Anna nor won over a la Morden. Because that really should have been a possibility in people's minds.

Re: Lorien's ship: I've always assumed it's a part of himself he's able to manifest and reintegrate at will, and that it comes along to the big showdown and beyond the Rim.