A couple comments about the stealth through Gilneas portion:

A fellow guild rogue and I grouped up and were going at it separately. We were both near the end when he sacrificed himself by pulling the area before the "boss". I simply sprinted through the scrum and made it to Creed without issue. None of the mobs attacking him saw me.

Once at the boss, I was going to use my sap and distract to return the favor. However, he had to reset his attempt so I went ahead and started the boss fight. Upon killing Creed, he was also given credit, and never even had to fight him.

I did video-guide for friends, with another (easiest and fastest) way to the boss with ShadowStep using. Try my method =)

P.S. I did this video in PreLive PTR build - nothing changes.

If you do this from the base of the southeast bridge and at a pretty low height it isn't hard at all to line up properly. Took me two tries.

World of Logs - Real Time Raid Analysis

[02:25:07.350] Sinnaabun gains Velocity from Sinnaabun
[02:25:27.437] Sinnaabun's Velocity fades from Sinnaabun
[02:27:17.175] Sinnaabun gains Velocity from Sinnaabun
[02:27:37.145] Sinnaabun's Velocity fades from Sinnaabun
[02:29:14.725] Sinnaabun gains Velocity from Sinnaabun
[02:29:34.797] Sinnaabun's Velocity fades from Sinnaabun
[02:31:17.876] Sinnaabun gains Velocity from Sinnaabun
[02:31:37.790] Sinnaabun's Velocity fades from Sinnaabun
[02:33:13.162] Sinnaabun gains Velocity from Sinnaabun
[02:33:33.213] Sinnaabun's Velocity fades from Sinnaabun
[02:35:12.488] Sinnaabun gains Velocity from Sinnaabun
[02:35:32.410] Sinnaabun's Velocity fades from Sinnaabun
[02:37:08.125] Sinnaabun gains Velocity from Sinnaabun
[02:37:28.184] Sinnaabun's Velocity fades from Sinnaabun

Isn't quite 120, so I would guess the 115 is accurate.

Didn't see any other info to confrim/deny this, so I posted.

So I just had a chat with a GM about two different topics. Yes, I know that GM's aren't necessarily the best source of information, but often they are the only ones until a blue posting appears.

1. It's currently entirely possible that only 1 Elementium Gem Cluster drops in a 25man raid instead of 2. The GM wasn't sure if this was intended or not and said that the question is currently being forwarded to the developers, with no answer so far. He said that I should wait for a blue post to clear up the situation, but that most likely there will not be any kind of refund if it actually was a bug.
   
   
2. There are several heroic (and raid finder) version of items that are bought with Valor Points (such as [Cameo of Terrible Memories] or [Belt of Hidden Keys]). I specifically asked (multiple times) if those would be available to players, in contrary to those items that were included in Firelands and supposedly should have been Crystallized Firestone gear, but never made it in the actual game.
   He assured me that these items were in the game and could be looted by players, and also that those would come directly through loot and not through some sort of token system.

Screenshots (in German):
Elementium Gem Clusters
Heroic Valor Items

I began collecting [Elementium Gem Cluster]s last night and found, after much frustration, that I could only open them outside of Dragon Soul. Has this been true for others?

I have been able to open each one inside the raid, usually immediately after killing the bosses.

My only (since it dropped on last boss) Elementium Gem Cluster only contained 3 shadow gems. My understanding was that it would be at least four. Anyone had the same?

I've seen anywhere from 3-8 shadowy gems per cluster. Generally I've seen 5-6 but only 15 gem clusters is a small sample size to judge this from.

I have so far been unable to open any of my Clusters anywhere. There are a couple of threads about this in the Blizzard forums, with the Customer Service thread having received Blue posts before being locked.

CS thread with Blue posts: Legendary Rogue Quest issue - Forums - World of Warcraft
Bug Reports thread: Cannot open elementium gem cluster. - Forums - World of Warcraft

Edit: As an update, Snopes reported that he formed a raid with a guildmate, zoned into and back out of Dragon Soul, and was then able to open his clusters. I'm pleased to report that after doing the same thing, I was also able to open mine.

On the note of the quickest/easiest route to Creed; You can drop down into the water on the left side of the bridge where the quest starts, and sap the stationary guard that is closest to the stairs leading up from the docks before you exit the water. Then you just wait till the two patrolling guards walk away and you exit the water and jump onto the docks. Then wait for your Stealth CD and re-enter stealth. Then run up the stairs, sap the patrol on the stairs, distract the group of guards closest to the outer wall, sap the single guard on the corner of the wall behind the group. Then you just watch the two patrolling groups of guards (one in the staircase leading down to the canal at approx 1:10 in the video Saedo posted above, and one on the wall section you are standing on) till you have a free route down into th canal. From there on, follow the video but I second the changes Aldriana mentioned at 2:00 and 2:17, with the addition that you can even sap the closest guard in the pair standing next to the wall for added safety. Making the suggestions I suggested to the start is both faster and has a lot fewer patrolling mobs and "tight squeezes" in between groups.