no, a jungle doesn't not become bigger. In my K all territory around is occupied by SH. But rss locations can appear on the valley territory, so I don't think that it can damage to this.

SteelTorin said:

no, a jungle doesn't not become bigger. In my K all territory around is occupied by SH. But rss locations can appear on the valley territory, so I don't think that it can damage to this.

The forest in my kingdom has an irregular edge, places where it is jagged, and places where it has a very long smooth edge, and  I have seen patches of trees spontaneously appear, so those are  the reasons I asked the question.

Still looking for the answer about  restrictions to resources inside the boundaries, and what happens if you find your town inside one

Yes so I believed , but note that there are lots of clan Strong Holds containing random  other towns. 

The other point  that interested me was that the new stronghold I saw over laps another,so who has jurisdiction over the overlap?

The overlap is that both clans control that area. If you are sitting in the overlap you still get your Valley bonuses, but the neighboring clan could exile you since you sit in their Valley as well.