From the description it says it adds some expansion components like ports, which I know are in a clash of kings. Does this make that expansion or both obsolete?

My understanding is that the 2nd edition incorporates the expansion content.

Not all expansion content is included (for instance the 4 player board from the second expansion - the once per game orders from the first expansion).

In my opinion the best parts of the expansions are included (ports, 6 players by default). The house cards have been redone for each team again - so I think the cards from the base game and first expansion are redundant in light of that.

I kind of miss the leaders/weather from the 4 player second expansion but that was never part of the 6 player core game.

So the first offers nothing new? But the second includes worthwhile content?

Yes, the second expansion called A Storm of Swords offers worthwhile content. It has a more balanced 4-player map, leaders for ALL 6 houses (not just the 4 in the SOS map), and Tactics Cards for all 6 houses, which give each house a single global effect for the turn such as "Control Westeros: +1 strength when assaulting castles/strongholds, and +1 to all influence track bids," or "Secure Hostages: steal 2 power from each player whose leader/s you hold hostage, AND if you defeat an enemy in battle who holds your leader hostage you can free them."

The 4-player map has some interesting game effects which cannot be translated to the base game/2nd ed. map, such as weather effects, and Ally Cards for House Frey, House Arryn, House Tyrell, and the Brotherhood Without Banners. When my group plays, we use SOS map if we have 4 players, with 2nd edition rules and a mixture of components from both editions. Otherwise, we use the 2nd edition map. We have yet to use the leaders on the 2nd edition map, but probably will next time we play.

The first expansion, A Clash of Kings, has a few things not incorporated into the 2nd edition--fortifications (+1 defense, build instead of consolidating power), special 1-time order tokens, and a set of house cards with greater variety, up to 5 strength.

Between the two, SOS is definitely sexier than COK, especially since the much of what makes COK so strong (6-player map, siege engines, ports) was already incorporated into the 2nd edition.

Yes , you need the extensions in the second edition as it is different from the 1st one and required the additional extensions so that it can run properly.

The second edition sounds like it is pretty much fine without further expansions.