Re: Should Illia and Decker have survived ?
Everything I've read about the Phase II series, is that it would have been without Spock/Nimoy. This is why you get the character Xon in the Phase II scripts, and not Spock. My understanding is that he didn't jump back onto the wagon until it turned into a major-budget movie (i.e. ST:TMP).
USS Galileo Galilei, NCC-8888
Prima Inter Pares