The skosh chart is pretty much right on, its a great tool to use for setting up your alignment.
I personally think that you can run more caster than it calls for, especially with power steering. It's a non tire wearing adjustment, so there's no reason not to run more. If you've got manual steering you'll probably want to stop around +3, as it will make it harder to steer. But with power steering there's really no issue, you can run about as much as you can get.
The camber settings are right on though, -.25 to -.5 degrees is fine on the street. I currently run -.75* camber on my car, and I've run as much as -1.0* degrees without significant tire wear issues. -1.0* is about the limit for the street though, more than that and you'll start trashing your tires. And really, to run that much on the street you'd want to be driving it around corners more than you drive it in a straight line. I was commuting 75 miles each way into the mountains when I was running -1.0*, and with the amount of backroads I was driving I probably was spending more time cornering that going straight.
As far as what "they" can pull up on "their" computer in most alignment shops, it will be the STOCK alignment specs for 1970, 71, whatever. It takes NOTHING into account, it's nothing other than the published factory specs. This is probably for legal reasons, which is hilarious, because the stock specs are more likely to wear out your tires and give you crappy handling than anything else. But the brilliant minds out there in liability don't get that the factory published those specs for bias-plys, and that a lot has changed since then.