Guild Wars 2

1) More customizable skills.
This is more important than all other suggestions by FAR. Guild wars 1 had a gazillion builds, all of them differently effective, there was no “one way to play”.
Now there are 8 classes that feel different from each other, but each class plays the same for that class.
You pretty much have only what weapon you choose to equip to be different.
There should be enough weapon based skills that you can swap them out to create the feel you want, at least as many as the “support skills” that you unlock with skill points.
Customizable auto-chains would be amazing, so long as they are balanced.
Elite Skills were your core in GW1. In GW2, they are just a long cooldown utility that is sometimes useful. This need to be revisited as part of the skill overhaul.

2) Less Zerg.
Look to City of Heroes/Villains as to how to do large group combat, where the players stacked buffs/debuffs and worked in conjunction to be effective.
Changing the build balance so that there is a valid non-heal-bot support build, making gearing more varied. (Personally, I don’t like the stats based gear. I would much rather see the ability to channel your ability points directly, with a cost to respec, and have gear that buffs effects, such as having a set that has piece bonuses to +condition duration, or +effect duration, or +effect #value, then for a full matching set, have a few unique effects, allowing for at most 2 or 3 full sets to be combined on any one character, a-la Adventure RPG style).

3) Player owned/run buildings.
Guild Halls, Private Quarters, something that’s more “personal” than a “bank with slots.” Let’s get less WoW and more Ultima Online.

Honorable Mention) Less Trahearne’s story, more MY story.

Honorable mention #2) More weapon types, morning stars, flails, crossbows, etc.

Having the exact same issue. Trying logging out and restarting the mission.

I closed the client, restarted the mission. This time I took a central position and tried to make sure none of the Vigil got downed. This seemed to work, as I was able to complete the misison.