David Boreanaz was a HORRIBLE actor in the first season. Not Ben season five level of suckiness(Ben is by far the worst actor the show ever saw...even Ashanti out did him).
And yes, season 1 fights did suck. They start to pick up SOME in season 2. Then in season 3, thats when they became REALLY good (its noticable in Anne how the fighting has changed).
It was his first big time role I believe. When they did the whole Angelus thing, they were scared if he could pull of that character. Of course he did it with flying colors.
Yeah, the battle scenes sucked hardcore in season 1. They found there swing at the end of season 2, just watch the sword fight with Buffy and Angelus.