They require wood to keep them going. Put a log in you hands and press RMB on them. Alternatively they'll power themselves if they have wood in their inventory.

To make a canoe you need a log, a wooden mallet, a chisel and a workbench.

Definitely! They're going to become more and more important as we develop this :)

We need eggs to make cake, so we will introduce a source at some point...

The potential for customisation will definitely grow.