Re: If VI had featured Saavik instead of Valeris as the traitor
Chekov as a co-conspirator? No motivation except for the false Piotr memory. Janice Rand would have been a logical choice, getting back at Kirk for kicking her off the ship all those years ago. And because he tried to do the nasty with her without consent.
I always thought she engineered the transporter accident in TMP via sabotage to get back at him for his double's antics.
"He clapped his captain—his friend—on the shoulder. Yes, this man was very much like James Kirk, in all the ways that mattered." --Christopher L. Bennett-- Star Trek: Mere Anarachy, The Darkness Drops Again