What if Gareth Thomas had decided to stayed on the show?

[Whitestar]

I've always wondered how the show would have ended if Gareth Thomas had decided to stay on the show. I recalled the episode entitled, "Pressure Point", a scene between Blake and Avon that caught my interest:

BLAKE The others have decided to go with me.
AVON [smiles] I thought they would. Not very bright, but loyal.
BLAKE That leaves you.
AVON I have thought about it
BLAKE And? [pause] Come on Avon, stop playing games. Are you going to go with me or not?
AVON Well, of course. I am surprised you ever doubted it.
BLAKE Thank you.
AVON Frankly, I don't see how you can do it without me. Your strongest enemies are going to be the defense computers. I am the only one qualified to tackle them.
BLAKE Yes, that had occurred to me. You better start getting kitted up. Do you want to tell me why?
AVON I like the challenge.
BLAKE You don't want to tell me why.
AVON If we succeed, if we destroy Control, the Federation will be at its weakest. It will be more vulnerable than it has been for centuries. The revolt in the Outer Worlds will grow. The resistance movements on Earth will launch an all-out attack to destroy the Federation. They will need unifying. They will need a leader. YOU will be the natural choice.
BLAKE Possibly.
AVON Don't be modest, Blake. You are the only one that they would all follow. You would have no choice. You would have to stay on Earth and organize the revolt.
BLAKE If there's no other way.
AVON There wouldn't be.
BLAKE That still doesn't explain why you're backing me.
AVON With you running the campaign on Earth, somebody has to take charge of all this.
BLAKE [Laughs] You want the Liberator.
AVON [Almost laughs] Exactly. If we succeed, the destruction of Control gives us both what we want.
BLAKE Could be you're planning just a little far ahead.
AVON [Nods] Perhaps. But sooner or later, I will have my chance.
BLAKE There's no hurry.

Curious, does this mean that Blake was originally supposed to leave the show? Was this the way Terry Nation originally envisioned it? Or, did the following dialogue between Blake and Avon inspired Thomas to leave the show? And what if Gareth Thomas had decided to stayed on the show? How do you think the show would have turned out?