Also, when I render the fur tree, the texture doesn’t appear properly. I assume its because I missed out this step: “Set the “Xrepeat” value to 2 (the Xrepeat button is underneath the “Load image” one).”
Prior to rendering if you press Shift+~ (being the tilde key next to the 1 key) all layers will become visible allowing you to render everything. Pressing this key combination again toggles back to the previous layer state.
For your texture question press F6 and look under the "Map Image " tab for the Xrepeat multiplier