I come from the metagame of a Diplomacy player where there is a philosophy of generally-acceptable initial moves for the game. Is there such a thing for A Game of Thrones? I've seen different opening move suggestions in the forums but with no comments. I'm fairly new to AGoT and trying to teach it to new players.

I'm most interested in opening moves and strategies for five-player games along with some reasoning behind them.

It's hard to say. Generally the Lannisters will move north in the Riverlands and the Starks will inch south but then it all falls to personal style (while sending a footman to castle black/the wall). The Tyrells and Baratheons might converge on Lannister to keep an early mustering from making them too powerful or the Tyrells will take the uncontested land. The Baratheons could send their fleet to attak the Starks or to keep Tyrell from making a navy on their side. The Greyjoys will generally want to destroy the Lannister fleet but they might also see more gain in keeping the Starks out of the water and take over the north.

In short, there's more either/or choices as opposed to a single excellent move.

I respectfully disagree.There were some impressive strategic posts on the old forums, and several moves which were regarded as standard first orders by most of the community then (of which I wasn't a part by the way).

Sadly interests since have moved more towards ASOS and away from these forums. I've haven't got any time this weekend to dig through my files for a quick rehash, but if you're patient I'll try to whip something up next week.

This strategy uses the Tyrell-Greyjoy king's Court fix (Greyjoy and Tyrell exchange position).

At the start of the game, it’s normally imperative to gain as many mustering points as possible, as a turn 2 muster will wreck most of your game if you have far fewer mustering points than the other Houses. So maximise marches in the first turn and take as many mustering points as possible.
Furthermore I’d heavily recommend playing with the port option of the Clash of Kings expansion (If you aren't already). It fixes some major balance problems, as you’re then able to retake seas by port. This is mainly important for Stark, as he then has at least a possibility to get Greyjoy out of the Bay of Ice. Just find the locations on the internet and use tokens until you decide to buy the expansion.

Each House has a territory which is his strongpoint. Try and take these in the beginning of the game and then hold them. For example, for Greyjoy this is obviously Ironman's Bay and for Lannister Stoney Sept (from which he can support his coastal territories). I won't spoil the others for you. I’d recommend www.Boardgamegeeks.com as a resource for strategy (such as this topic: http://www.boardgamegeek.com/thread/15178 ). (You’d better start digging from the oldest posts onward, however.)

Now for the first turn orders:

Stark: Winterfell: March-1, White Harbor: March+0, Shivering Sea: March+1
March from winterfell to White Harbor (perhaps putting a foorman in Karhold to gather power). Make sure you march to the Narrow Sea after Baratheon has marched his ships (otherwise he’ll kick you out). Your +1 March will make sure you can kick him out. From White Harbor you can then march to Moat Calin or (if Baratheon moved his ships before you and you’re feeling cocky) all the way to Crackclaw Point.

Greyjoy: Pyke: March-1, Greywater Watch: consolidate, Ironman’s Bay: March+0
Take the sunset sea, Flint’s Finger and Seagard. Keep your eyes open for Riverrun, though Lannister should support it strongly.
Or, if you fancy an attack on Lannister:
Pyke march+0, Greywater Watch: march-1,Ironman’s Bay: support+1
However, an experienced Lannister will raid the support, leaving you even without the Sunset Sea. You might be tempted to wipe Lannisters defence+2 fleet of the map, but that would require both of your ships, leaving you vulnerable to a next turn muster from Riverrun straight into Ironman's Bay (as Lannister is first to muster). If Greyjoy loses Ironman's Bay, his chances of winning are most likely over.

Lannister: Lannisport: March+1, Stoney Sept: support+1, The Golden Sound: Defence+2
(if Greyjoy pays a support on his fleet, you must change defence+2 to raid with the raven)
Take Riverrun, keep supporting from Stoney Sept and keep an eye on Greyjoy. These orders are pretty much fixed, as it's the only way of preventing Greyjoy from invading you (barring some pretty pursuasive treaty-building).

Baratheon: You can take King’s Landing on turn 1 should you desire: Dragonstone: March+1, Kingswood: support+1, Shipbreaker Bay: March+0
Then you can take King’s Landing on turn 1. Make sure you have an understanding with Tyrell before you do this, or he might attack (or raid) Kingswood from the Dornish Marches (and win with Tyrell) royally messing up your plans.
More conservative move: Dragonstone: March+1, Kingswood: March-1, Shipbreaker Bay: March+0
Take Storm’s End (park 2 units there if Tyrell can still move from the Dornish Marches) and Crackclaw Point, or set up for an attack on King’s Landing on turn 2. Your weakness is supply, however it's not wise to pursue barrels on turn one, because a turn one muster will likely cause you to lose the game.

Tyrell: Highgarden: March+0, Dornish Marches: March+1, Sunset Sea: March-1
This gives you the option of immediately going after Baratheon, should you desire.
Gaining power is your weakness, try to get a footman to the Arbor or Yronwood for power. The rest can go towards gaining musterpoints.

Hope this helps .

You reference balance issues that are "fixed" by things like the ports and the errata change to the Tyrell/Greyjoy King's Court.

I don't want to rehash what is likely an age-old debate but I haven't had the chance to find the old topics that spurred the debate. Can you reference some threads from here or are they all gone to the archives? I can't access BGG from work for some strange reason

I referenced those 'fixed' issues since you seemed most interested in 5 player games. I had no idea how invested you were into the game, so I just mentioned those in case you only had (an old version of) aGoT.

I'm afraid those strategy-threads were all part of the long gone old forums. They're gone.... ..Pity, too. There were some pretty good threads on the old forums. I've got some saved on my PC and still consult them sometimes...I think the BBG-threads are about all that's left.

Genejack said:

I, of course, meant a support+0 at Ironman's Bay.