The inconsistencies around spike in season 2

I can think of 3 off the top of my head.

1. When they’re researching him, Giles says that he’s barely 200 but we see later that he was at most 120

2. When Spike first meets Buffy, he tells her that the last Slayer he fought begged for her life, but in the flashback in season 5, we see that Nikki doesn’t even say anything as he kill her.

3. When they first fight, it’s relatively equal but Spike does best her imo, but later on in the season, Spike hires the order of Taraka to take Buffy out which implies that he now all of a sudden wouldn’t beat her when earlier in the season that’s what he did.