If Zombie had done something like "High Tension" and made Laurie the killer all along in the sequel I think I would've liked it better. And her shadow shelf takes on the guise of Michael. I think that would've been a worthy sequel.
Back to the first film, I liked the attempts to humanize Michael. I think they showed he came from an abusive home-at least verbally abusive, and he anger issues, and took out his frustration or rage on animals, which could be some indicators of possible antisocial personality disorder. I think there was more behind his killing his family than boredom. They seemed to be holding him back, restraining him, insulting him, abusing him, and he just got tired of that. He let go, and he did it in a very violent way. I think his violence was about taking control, trying to assert power over his own life, and other the lives of others. I think he wanted people to fear him.
For me, I just never got the indestructible, evil incarnate Michael from the old films. At least with the other icons of that era, Freddie, Chucky, Pinhead, and Jason, there was some supernatural explanation to explain why they kept coming back again and again. But with Michael? He's just too evil to die? That didn't work for me. Though I did enjoy Donald Pleasance's pontificating about it. He really knew how to build up to an epic confrontation, something McDowell's Loomis unfortunately didn't do.