It isn't that Pat was insufficiently sexy, it's that she had other obligations. Remember, most pilots fail, and B5 wasn't picked up until more than a year after the Gathering was filmed. She didn't have a contractual guarantee so she took other work and wasn't able to come back for the first season or most of the second. Incidentally, she just gave birth six weeks before this episode was filmed.
JMS made it clear in the script books and Pat expanded on it in her book (Pleasure Thresholds) that the studio flat out didn't want her for a number of reasons (more stunt than acting credits, and possibly bad feelings from an exec who tried to casting couch her) and ensured it by a too-low contract offer. When she passed on the offer, JMS was away and couldn't try to re-open negotiations.
I was unaware of that. Thanks.
This episode has another evil Psi Corp thing, sleeper agents. does Psi Corp do anything except sit around thinking of new ways to be evil?
Also, were Talia and Ivanova sleeping together?
Hypothetically, yes. The problem with the Psi-Corps is that it was created to brutally oppress telepaths because people hated and feared them but the releaties of psychic combat mean that all of its agents must be telepaths. You can see how this is problematic.
EarthGov's intent was that the Psicops would be their equivalent of the Jewish kapos and Ghetto Police in Nazi Germany, collaborators who fuck over and murder their own people in exchange for preferential treatment.
What actually happened is that the Psi Corps became a nation unto itself, with it's own unique culture, technically under the authority of EarthGov but in reality separate from Earth culture and with no real loyalty to mundane humanity.
The law that Telepaths have to take drugs that fuck them over and lead or suicide, join the Psi-Corps, or go to prison forever was passed by EarthGov, not the Psi-Corps. In human space, Telepaths aren't even second class citizens. Their status is somewhere between that of blacks in apartheid South Africa and Jews in Nazi Germany. Those who refuse to bow to the system are either imprisoned for life or just murdered and the mundanes really don't give a shit because they're scared of the telepaths. It's like being a mutant in Marvel only worse.
People like Bester are acting wildly outside the law to create what they believe to be a better world for telepaths. That requires doing some shady and unethical stuff, but they genuinely believe that the goal of freeing telepaths from mundane oppression (and oppressing mundanes in turn) is totally worth the cost.
In that way, the Psi-Corps and the telepath Underground Railroad are very similar. The difference is that the Psi-Corps wants to take over the system from within while the Underground Railroad just wants to get away from it.