E.A.D.
Mechanics guide
E.A.D.
I think the wiki is exactly the “manual” you are looking for.
The game is incredibly vast and complex and I doubt that any small group working at ANet could cover everything we ask about. (See the weekly, “Stupid Questions” thread at the GW2 sub-reddit.) Worse, the game changes every two weeks (sometimes substantially, sometimes not) and any manual needs to be kept up-to-date. That’s a lot of labor that could be directed towards fixing bugs or building a new fractal or a living story.
Fortunately, the company was smart enough to host the official Guild Wars 2 wiki. The community that edits it tries to cover everything and tries to ensure that most players can follow and make use of the explanations. Most stuff asked/answered here or in Reddit winds up on the wiki.
Sometimes, it won’t be obvious which article covers the mechanic of interest to us and it’s often difficult for the volunteer writers/editors at the wiki to know how best to present the information. In which case, we might have to ask specific questions here (or on guru or reddit) in the meantime.
The wiki covers your topics as follows:
- Out-of-combat: not covered directly in combat
- Cooldown: not covered directly under cooldown, but covered indirectly under interrupt
- Blink: covered under teleport and sort of covered under blink.
- Projectile: not explained under projectile.
In my opinion, the only reason (1) & (2) above aren’t already covered on the wiki is no one has stopped to ask about it there (or if they have, no one has felt it a priority to update the relevant articles). That’s easily fixed by posting your question on the talk page.
As for (4), I think that falls under, “GW2 is a game — sometimes, mechanics are the way they are because the game would be boring otherwise.” If projectiles were too fast, NPCs and players wouldn’t be able to dodge them; if players were any slower, combat would be a lot less dynamic.
The wiki isn’t a perfect tool, in no small part because its staff is all-volunteer and human (we all make mistakes, we all burn out or disagree with each other). However, I think it’s an amazing resource, covering probably 80% of topics extremely well, 15% better than sufficiently, and only 5% or less aren’t covered as well as I think they should be. If it’s not on the wiki, I doubt it would be covered any better in an ANet manual.