Yeah, but the primordial urge - to bite people - wasn't there when he was able to bite Buffy.
I still think, from what we've seen in 'Smashed', that Spike would've bitten anybody
but Buffy (or perhaps Dawn) if the chip had stopped working entirely. His love of Buffy curbed his desire to bite her, but maybe not forever.
And Spike would never turn Buffy, because of what happened with his mother.
But those revelations about what happened with his mother only came to light after he got his soul back. Then Spike fully understood that it was the demon lashing out at him and not his mother. Before that? No, Spike didn't have that capacity to realise, he didn't really understand the difference between demon and soul, therefore its entirely reasonable that he would turn Buffy. Unless you're implying that he never turned
anybody when he was a vampire, which seems unlikely.
People always say that, but Buffy didn't want to bring him to the light, either.
Spike came to her Birthday party and she let him stay. If Spike had been willing and able to hang around her friends and be with her 'in the light', why wouldn't she have wanted that?
This, from 'Older And Far Away':
BUFFY: Hey! Passive Aggressive Guy! Seriously, wanna take it down a notch or two out there?
SPIKE: What, poor, dainty Richard can't take a joke?
BUFFY: We do not joke about eating people in this house!
BUFFY: I should have thrown you out the second you got here. I was insane to think you could ever just hang out with my friends.
Buffy tried to tolerate him with her friends but it didn't work. Spike wasn't the 'hangiing around the house' type.
And look at the comics now, Spike is one of the gang and Buffy is cool with that. But before that he wasn't able to just hang around with them- he's still pretty unpleasent.
I mean, before Buffy came back from the grave, Spike was always at her house taking care of Dawn, "in the light."
And after Buffy came back he hardly ever interacted with Dawn or the Scoobies again- he stopped caring about Dawn and went back to lurking about- 'Flooded', 'All The Way' etc.
Spike wasn't interested in spending time with Buffy's friends, he was simply interested in isolating Buffy from her friends and persuading her that they were the same- 'Life Serila', 'Smashed', 'Dead Things'.
Spike didn't want to be 'in the light' just like Buffy didn't want to be 'in the dark'.
Basically I don't think Spike was a nice guy at all before he got his soul. He was a nice
demon, and that's an entirely different thing- because, well, he's still a demon.