The rule book says that a psycher's powers are used how the codex allows. In the eldar case it says all of the above ^. It does clearly state that all the powers are used as described in the 40k rule book. The 40k Rule book just tells you to refer to the specific army (codex) rules for using psych powers. In the codex: unless otherwise noted, the powers are used at the START of the Eldar turn and do not require line of sight to target. Fortune/Guide/Doom never say they are used in the shooting whereas Mind War and Eldritch Storm clearly say "in the shooting phase". Also, Mind War says that it requires line of sight even though the main rule is that none of the powers need LoS. This is why eldrad cannot jump out of a transport and use Fortune/Guide/Doom, because he just finished his movement when he jumped out, thus NOT the start of the Eldar turn. He may not use the powers when inside the transport because of the transport rule. You may however use your Fortune/Guide/Doom then embark into a transport because you use them before the movement phase. Your right, it does not say that Fortune and Doom can take place durring the assualt, this is because they don't. They take place at the start of the turn (before movement/shooting/assualt). Nothing about the assualt phase prohibits the use of powers that are used at the START of the turn.
The codex Clearly says that , unless otherwise noted, the powers work as described in the Psychic Powers section of the 40k rulebook. It also says they are used at the start of the Eldar turn. OH LOOK, it has just been otherwise noted. Just as Eldritch Storm and Mind War have been otherwise noted to take place in the shooting phase. Ive asked for many people's opinion on this, not saying that its 100%, but it is very clear when looking at both the rulebook and the codex. No one has dissagreed about it where I play. They may not like the Eldar "cheese" but they still do not dissagree.
Ambiguous rules strike again. I went through the rulebook pretty thoroughly when I was first researching Psychic powers to try and see how they worked. One of the things I really wanted to know was whether I could use Psychic powers while locked in close combat.
So during my research I read the Psychic Rules Page 56. The last paragraph of which stated Psy powers are subject to the usual shooting rules. I then read the Eldar codex and through the Farseer powers. The Eldar codex said they followed the normal rules for Psychic powers and were used at the beginning of the turn and didn't need Line of Sight.
Now, by this point I had a few things in mind: While I didn't need Line of Sight and used the powers at the beginning of the turn, every other rule for shooting was followed, and going by the examples they give in the Psychic powers section would mean I still had to direct all my powers at one target, etc. Another thing was melee, what if I'm locked in close combat? So I read about shooting while locked in close combat which led me to page 44 of the rulebook under the heading "Shooting into and out of close combat" Which states that models can't shoot into and out of close combat... I didn't really pay attention to the "..in the shooting phase" part.
I like the idea of being able to use Psychic powers while locked in close combat if I can, the idea of it never made sense to me though. Just because the Assault phase is the last phase of your turn doesn't mean your guys and gals and alien creatures paused in their fighting to wait for everyone else to finish moving and shooting. I just imagined it as always going on and you only worried about what happened while everyone was moving and shooting, in it's own time.
Using the conditional "...in the shooting phase" seems like abusing the intent of the rule by pointing out the technical wording of it. Who doesn't shoot in the Shooting phase? They say that the attacks from pistols and such are taken into account through the results of close combat (Another thing that never made sense to me, especially when my Fusion Pistol is Strength 8 and my Eldar Harlequin is Strength 3 or 4) and that your unit is completely taken up in the swirl of combat.
Anyway, it doesn't quite make sense to me but if you can use Psychic powers while locked in close combat, I guess that's okay. I've always played it as that I couldn't.