Angelus ALWAYS looked down on Spike, right from the moment Spike was sired. Spike has always seen Angelus as competition, especially for Dru's affections.
Angelus has been gone for over almost a century, as has Darla, and, whether he likes it or not, Spike has missed them. He's missed having someone to act as the adult while he skips around as the child. Angelus being back makes Spike thinks that he can go back to just having fun rather than the one in charge.
But, without Darla around to take Angelus' focus, Angelus' attention fell completely on Dru and, with Spike being in the wheelchair, he didn't have the option of fighting back, of proving himself to Dru because he was physically weak.
I don't know, though, that he'd be all that in favor of shoving Angel's soul back in him. Not at that point in S2, anyway. He just wants Angelus out of the way - preferably dead, I think.
He'd have preferred dead, certainly. But I can't help but think that if Buffy had said the deal was that Spike stall the ritual with Acathla long enough for Willow to give Angel his soul back, and then he'd be allowed to take Dru and leave town, he'd definitely have taken that deal (after a few minutes of arguing, of course). That would have worked out better for him too, I think, because it'd have been easier for him to keep Dru around, imo.
Returning Angel's soul is a form of torture inflicted upon Angelus, and I still think that Spike would rather go for the quick kill than risk the possibility of having Angelus reappear at some point in the future.
Merrick agrees: Spike did seem to enjoy taunting Nikki Wood quite a bit. Perhaps that was the exception that proves the rule though, as it seemed to be very personal to both of them.
Okay, so what your saying is Spike likes the fight, torture really isn't that fun. Spike likes to win after a good brawl. So Spike would be against Angel getting his soul back, it's just a handicap. Spike wants to beat Angelus in a straight up fight.