Everyone is a bit different. Grip make a difference, because it will affect your draw length--I will draw at least 2" more with a high wrist vs. a low wrist.

Nothing personal against Mr. Asbell, but there's a lot he teaches in his books I don't agree with at all, and some I know is just plain wrong. There's no one perfect style for everyone--get the basics and work on it from there.

I wouldn't worry too much about spine/tuning until you get a good solid form established, because how you shoot can affect what spine you need and how you tune.

Not sure what's being described as a "broken wrist", but if it's the same as my definition (low wrist grip), it's no problem to cant the bow using that grip--as BC said, it's actually very common.

I'd have to disagree with most every longbow shooter having a broken wrist grip (again, if it's the same as my definition). I see and shoot with lots, and except for those shooting Hill style grips (straight), most seem to use what I'd call a medium wrist grip (including me). 'Course that's not a straight wrist, so I guess it could be called a broken wrist grip? If that's BC's definition, I'd agree 100%--almost never see anyone shoot a longbow with a high wrist.

Chad