All good questions. Im not the best of the posters here, but these are my findings -
1. I would chose a 2 way truss rod simply because it gives you adjustment both ways. 2 way truss rods however can be a little larger than most one way rods, so little more wood may need to be removed for installation. More wood out means a little lesser strength to the neck. Most 2 way rods are designed to make the whole rod turn in the neck for its working. The friction between the rod and the channel and added forces of the strings make such rods a little harder to turn. The one way rod like the warmoth rod, only turns the nut to bend the rod. So they are easier to turn. There are 2 way rods that work with just the turn of the nut and not the entire rod. I would chose those.
2. I see advantages to the overall stability of the neck through weather changes. Also the added stiffness will affect your tone to an extent and make it a little brighter. The bars need to be installed correctly though and should fit very snug in their channels. They also need to be glued in to replace the strength lost by the neck when those channels were routed out.
3. The only advantage is that no material will be removed from the neck for the stiffening bars. With one piece necks however these bars will help as the wood will want to move with changes in the weather. If that one piece is made from quarter-sawn wood, then the stiffening bars will help to a lesser extent.
Multiple piece necks are normally oriented with symmetrical end grain to cancel out the warping, so the requirement of stiffening bars in those necks is reduced. I would still use stiffening bars in any wooden neck to be on the safe side.
4. IMO, the bars should be parallel to the truss rod. Its a matter of personal preference and different people do it differently. I would do it parallel as I feel it will resist the string pull better.
5. 24" max. overall length
Last edited by suraj : 10-07-2013 at 04:23 AM.