It's not known if L'Anse Aux Meadows was their only settlement in North America. From the descriptions of Vinland it seems likely that they explored the Gulf of Saint Lawrence. They might have gone further, we don't know.

Timber was very valuable to the Greenland settlements, but not valuable enough where you would export it to Europe. Vinland wasn't barren of forests. Perhaps you're thinking of Markland (Labrador)?

They took wood from Vinland to Greenland. They traded mass amounts of walrus ivory from Greenland to Europe (it was perhaps 99% of their exports), in exchange for tools and finished goods.

The Norse Greenlanders were a European civilization and it was very important to them to keep access to that European trade link. They were not fully self sufficient like Inuit people. So the Vinland settlement was perceived as just a source of materials for Greenland. I believe they likely explored further but any further settlements would have been perceived as too far from the civilizational link in Greenland.