To expound a bit;
1) The Hird are (presumably) something like the military officers of a village. You'll need to have the Chieftain (I don't think the Lawspeaker can do it; could be wrong) make you a Hirdsman to be able to use their gear. There's also a usable skill or two that the Chieftain can use to fiddle with the Hird.
2) No, trees don't regrow from stumps. You'll need to refer to
the Tree Replanting topic. Apple cores and mulberries work just like fir cones, by the by.