The way I read it, Wood Shape lets you literally change the shape of a piece of wood, much like you could do with a piece of clay (except for the fact that you do it instantanelosly, without actual manipulation). In fact, as the spell states, even simple moving parts may not work.
Twine is not just "fine detail", it is processed material (requiring to remove the bark first, then take the inner layer) and goes beyond the effect of the spell.
For what concerns using it on plants in general, plants are considered objects so no problem there, as long as they have a wooden part (so hay would not be a valid target).
Twine is not just "fine detail", it is processed material (requiring to remove the bark first, then take the inner layer) and goes beyond the effect of the spell.But couldn't you say the same thing about any wood from a tree? You have to remove the bark to affect the wood. Shaping the wood into anything requires processing the wood.
Twine would just be the inside of the bark woven together.
Sorry, I am not sure I got what you mean here... Are you implying that you need to remove the bark to target a piece of wood with the spell?
Anyway, what I was trying to point out was the difference between an elaborate process such as making a bundle of twine, which also requires you to isolate a small part of your target, and simply altering the shape of the target piece of wood (worked or unworked) as a whole. The latter case is how I believe this spell works, reinforced by the wording of the spell suggesting that something as complex as a door is crude at best, and moving parts may not work. To me, creating a bundle of twine seems more complicated than crafting a hinge.
That said, I suppose that with "creative" spells like this, you are bound to see some table variation, so you are probably better off asking your GM. Personally, even though I don't think this is supposed to work, I may allow it as long as it brings some creative problem solving to the table (and considering it is hardly game-breaking).