What's this?!

[Kuruharan]

In fact, the only relation I could describe as feudal is that between King Aragorn and Prince Faramir, whereby one is granted land administration in exchange of fealty, counselling and military aid.

I’m afraid I can’t agree with that. First of all, on a very small scale, you have the oath-taking of Pippin to Denethor (although it may be an important point that Pippin did not appear to swear to Denethor personally). Secondly, there is the matter of the Princes of Dol Amroth (who appear to be virtually independent sovereigns, but Imrahil speaks of owing fealty). Then there are all of these Lords of Somesuchplace that come marching in to Minas Tirith.

What the situation between Aragorn and Faramir does indicate is that Aragorn probably wasn’t going to change the system (whatever that was).

Gondor was, in some ways, an ideal state.

Hmmm…not sure I agree with that either. Tolkien certainly viewed them as being a positive realm, but I’m not sure ideal is the right word. The Gondorians were always portrayed as being very proud of themselves, particularly in the days of their power. Tolkien’s feeling about this seems to be a bit ambiguous. Proud people tend also to be some of the more fractious. I have a hard time believing that the Gondorian nobility could have had the power to cause trouble (and in this I specifically mean that the lords had military forces at their command that were loyal to them) and not have done so at some point out of the goodness of their hearts. They were a virtuous nation, as far as that goes, but they were not all saints.

Maybe Gondor is run almost as a 'commonwealth' during this time?

Hmmm…there’s an interesting idea.