If you have a variety of aluminum arrows, I wouldn't bother with a wood arrow test kit. This is because they have consistent spines that can be converted to wood arrow spine. When I get a bow I want to shoot wood with, I tune with aluminum and then convert to wood. For example, If the bow tunes with a 29" 2117 (77 lb spine)that tunes well with 200 grain total point weight (broad-head and adapter), you can be confident that a 77 lb spine wood shaft with a 200 grain point will tune well at close to 29 inches length. Three rivers has a chart of aluminum spines on their website. I haven't found converting spines of carbons to wood to be as predictable. As always in traditional archery, your results may vary.
In regards to your draw length question, your arm holding the string should be pulled into a strait line with the arrow, if not you are under drawing. When you say front of the bow, do you mean the side you can't see when you when drawing? That's the side you should measure to for arrow length.
AS far as advantages of wood arrows, the only ones I see are you get to make them and they look better. Disadvantages are they are less durable, but you get to make more that way. They perform just as good as aluminum and carbon if properly tuned.