Follow-up to the now-deleted post.
1. You HAVE to straighten some heads rather than just planing the gasket surface. If the head warps, the overhead cam saddles go out-of-alignment. Straightening the head gets the cam saddles back in-line; or at least closer. The straightened head may need no align-boring/honing of the cam saddles, or will need less material removed which improves the chances of getting proper valve lash/lifter preload. Similarly, if the head is straightened before machinework, the valve guides are more likely to be concentric with the seats, again minimizing the amount of material needed to "correct" a warped casting.
2. True enough, after "straightening" the head, you'd probably need to at least skim-cut the head gasket surface. A proper straight-edge and a careful examination
would tell that tale. Same deal with grinding the valve seats. They'd have to at minimum be tested for sealing, and likely "touched-up".
3. I had concerns about the torch screwing-up the heat-treatment of the head. But where he's pointing the torch isn't a wear surface; and it's possible the head wasn't heat-treated to begin with. Any quality aftermarket head for our old V-8s will be heat-treated ("T6" is the common result) but I wouldn't promise that the OEMs are doing that. At minimum, they don't tend to advertise it. Given a choice, I'd rather NOT use a torch. But I've been wrong before; and I've never personally straightened an aluminum head.
4. Of course he'd need to check the straighness/flatness of the BLOCK head gasket surface as well as the gasket surface of the head. Moderate chance the block needs work, too.
5. Yes, the chick has a screw loose, (perhaps SEVERAL screws loose) and the guy reminds me of Buddy Hackett in The Love Bug.