Follow the wiggle 100%! Do not cut through the grain!
I would statrt at 67" nock to nock. Your 2" width at the fades is good to start with. However I would say that 1 3/4" is likely to be wide enough. You can reduce the width later on in tillering if the bow is showing no set. Narrower and thicker is more efficent than wider and thinner. You don't want to be too wide but nor too narrow.....Also no problem to work the tips width down to 3/8ths but leave this until you are at 24" or so of draw so that you can check true braced alignment.
Fade length is personal preference really. You can go as short as 1 1/2" to around 4". The shorter and more abrupt the fades the more likely you are to run into trouble. Longer , shallower fades help to make the transistion more gradual and spread the load. If I were making a 67" / 27" draw bow I would probably make the fades 2 - 2 1/2".
It is best to have the lower limb a bit shorter because when bows are made this way as appossed to centered grip the bow will 'carry' much better and balance in your hand. Centered bows will always feel lower limb heavy. Might not sound like much but it is one of those things that makes a difference
Remember a pyramid bow will have little thickness taper. This (more or less) constant thickness dictates a circular tiller, same thickness = same safe bend. Make your self a tillering gizmo or use a 6" straight edge to help judge the bend.
