I forgot Cleo offered to turn the Doc in episode 5 (they were suspecting all of the vampires were going to be after him anyway, and it may be best to be turned by a friend). He refuses, but there were a couple of interesting points made.
He says he would rather be turned by Owen or Scott - this seems to come from a place of strategy more than anything (he worries a vampire's entire line all the way back to the primary sire would need to be taken out in order to be cured - if Cleo turns him, then Scott -> Pyro -> Cleo would all need to die for him to be cured, which we know isn't the case, but he didn't know that at the time)
This implies the Doc was open to the idea of being cured if he had become a vampire at some point earlier in the series, meaning there was a point at which the Doc was... less suicidal than he was in the later episodes. It's an oddly hopeful Doc, all things considered.
Cleo indicates that they are fully willing to die if Legs eventually wishes to be cured, and the Doc reiterates that he doesn't want to take that risk.
I haven't watched the early/mid episodes in such a long time, I forgot there was a point where Cleo was far more suicidal than the Doc, and it's fascinating (and, you know, heartbreaking) to see that shift in later episodes where Cleo expresses the desire to finally live for the first time in her life, while the Doc begs to be used as a weapon to detonate if all else fails.
