Anyhow, your elements of metal seem pretty off to me...
Like I said, everyone has their own definition of metal, and nothing any of us could ever do will ever even remotely diminish that. It's called opinions. We've all got 'em and they're never going away. But like I said, I do enjoy talking about it.
What? A certain amount of technical metal has this, yes, but that's nowhere near universal. Obviously bands try to avoid making mistakes, but...have you ever heard Venom?
I'm not specifically talking about techicality per se'. It's a very hard thing to explain, but I hear it in every single metal band I've ever heard. It's the approach towards the music. Rock bands aren't necessarily less talented or precise, it's just that rock is based on a groove element that is lessened even in the most groove-based forms of metal. It's a dirty, earthy sound. But all the way back to Black Sabbath, the way that the instruments flow with each other very different from the more organic groove of rock music. Whatever the difference is, it feels more precise to me, so that's the term I used to describe it.
Not any more so than rock
Are you kidding me? Wrong. Is having multiple riffs not one of the defining elements of death metal? A typical rock song would be like Rebel Rebel by David Bowie. One riff, a chorus, a bridge. Only the prog bands like Yes have as many changes and varying passages as metal, and in those cases it often happens over a 10 minute song whereas in metal there are 10 minute songs but there are at least as many 4 minute songs with those changes and passages in them. It's the verse chorus verse distinction. Maybe the more verse-chorus based metal bands sometimes do stuff that is as simple as definitive rock music like Zep, AC/DC, etc. But even bands like Pantera and Metallica have like 5 riffs per song. Zep and AC/DC never did that. Indie rock bands don't do that. No genre does it as often as metal.
Okay, for the last time, vocals don't define a genre. But even if they did, most thrash and trad metal doesn't have harsh vocals, and that's about 30% of all metal (that number comes from nowhere, by the way).
Okay, for the last time, everyone defines genres differently. It's one thing to say that vocals aren't the ONLY thing to define a genre, but it'd be downright mentally retarded to say that vocals don't have anything to do with defining genres. It's not an aspect of the music or something? Should we ignore the guitar and drums too? Maybe bass is the only thing that defines genres...
I don't consider trad metal to really be metal. Borderline metal, perhaps. But I was NOT talking strictly about harsh vocals. I included aggressive, angry vocals like Slayer and Metallica. Maybe now adays you get angry vocals in rock bands by the dozen, but back when those thrash bands came out it was unheard of in rock. And even a lot of the operatic metal singers have some anger in their voice.
For the last time, lyrics don't define a genre. But even if they did, there's plenty of metal about just chillin' out, while there's plenty of rock that plays around with satanic themes.
Reread my above critique about claiming certain aspects are irrelevant when defining a genre. I know there's a lot of metal that doesn't have individualistic or satanic lyrics, but I already explained what these aspects were, and I didn't say they were something all metal bands had. There is undeniably more satanic lyrics in metal than in any other genre. Furthermore, as I stated, I was defining my own definition of metal, rather than trying to come up with something that would be applicable to the whole community, since nothing of the sort could exist.
...in some genres of metal. If you want to define a subgenre, this would work. But this applies to thrash, a lot of death and trad metal, and a certain amount of power metal. But what about black metal, folk metal, and doom metal? Not applicable to vast swaths of metal, so it's no good. Also, more and more rock and even punk-pop bands are using chugs...kind of annoying, tbh.
Doom metal and black metal are still based around the chugging machinery sound just as much as death and thrash. I'm pretty willing to bet that all metal bands have at least some connection to this type of thing. Bands who don't would be bands I probably wouldn't consider metal.