Buffy having "special pick up hammer" powers makes no sense to me. There's no reason for her to have access to a troll hammer...

Also, Angel explicity says that Buffy is stronger than him; why wouldn't she therefore be stronger than Spike?

Another thing--Buffy can take on five vamps at once and be fine. Do you think that if Spike were to take on five slayers at once, that he'd not end up dust at the end of it? I don't think he'd survive. He is a skilled and aged fighter--of course. Stronger? Not so much.