Another set of questions I am trying to find information on or, in lack of information, make up my own aswers. Any input is welcome
Aragorn is supposed to reclaim Arnor under his crown during the 4th age. But what is the status of the northern kingdom?
Of the old cities, only Bree seems to remain in any form other than ruins. I don't remember the description from the book, and I don't have it here, but I think the book also had a closed gate at night. This seems to indicate that Bree has at least a palisade around it as a defense. So that the hobbits considers these areas as much more dangerous than the Shire could be more than prejudices. The Shire on the other hand seems to have open villages anyone could walk into. Their care-free nature indicates to me that the Brandywine river is not something you can get across without a boat.
But what of the rest of the northern kingdom?
Southeast of Cardolan, directly to the west/northwest of Rohan, do we have Dunland, which seems to be a tribal or clan society.
Tharbard is in ruins and is just a place where you can cross the river.
According to the Encyclopedia of Arda did Halbarad Dunadan only had 30 Rangers with him to fight for Aragorn in the War of the Ring. This makes me believe that one of these three options have occurred
a. The Rangers are almost extinct
b. The Rangers was to geographically divided to gather a larger force in time
c. The Rangers was to politically divided, so they didn't care to come to the aid of their chieftains.
There is a large are between Bree and Dunland. Is this an empty space, or does people live here? I assume that any settlement between Loudwater and Misty Mountains (The triangle that would be if you place Rivendell and Tharbard at the edges) would have a lot of problems from raiding orcs. But the old kingdom of Cardolan is probably inhabitable but without any central government. Maybe it is more equal to the frontier of the old wild west?
Are there any more factions?
I'm not sure that that the revival of the Northern Kingdom receives a positive welcome everywhere. At some locations does Aragon might he meet resistance, but the show of force is enough (just showing up with his guards), at other location might he even have to use force. From Gondors view, they are just bringing back law, order and civilisation to the land. But from the locals, they might very well consider Gondor to be an occupation force. This could create unrest for a couple of decades until everything settles down.