Let me try to address all of your questions (There's a lot to chew on here
)
The FW FAQ states that you can take Rangers as an elites slot. Though they make total sense from a fluff standpoint, they decided to allow you to take them as the Elites outcasts slot. This means that you cannot take another CWE FA or Elites unit for that slot....and they aren't scoring...they blow for Corsairs.
You can take Wraithguard as the elite outcasts slot(though this makes no sense from a fluff standpoint). Take a Prince, use the deepstrike rule that the Prince that can give to 3 units, add 10 Wraithguard, and watch the wackiness ensue
. I did it once. Only because I could. Scared the bujezus out of my opponent who in turn totally overreacted to them and forgot about objectives.
I equip at least one squad with jetpacks and EML's. Nothing else. It's a good objective holder and general pain in the rear of your opponent with their jump-shoot-jump moves.
Venom squads should have at least a shuriken cannon in the unit. You can fire it if the venom moves 6" or less(shuriken cannons are assault weapons
). I usually add a fusion gun too if I have the points, though I keep these units as far away from enemy units as possible and only use them to attack light flanking units. I prefer to use Falcons for the transports. They are resilient, have a great weapon in the Pulse Laser(at BS4), and can generally keep your fragile over-glorified Guardians alive to take objectives later. I always take las blasters for the simple reason that you don't want to be anywhere near 12" of an enemy unit(think T3, 5+ armor...)
The Void Dreamer can't take psychic powers from the book. Check the FW FAQ on psychers. It's pretty clear on that. Void Dreamers are a bit tricky to use as they aren't all that great(aside from the Withering psychic power which is quite the slice of awesome) I use him with a jetpackand neural shredder to accompany a Voidstprm Squad with two fusion guns. It's a great little distraction unit that your opponent can't avoid dealing with.
I usually don't take a Holofield with my Warp Hunters(I have two of them), though I can say that it would probably be worth it if you were taking only one in an allied formation.
ALWAYS, ALWAYS, ALWAYS take shuriken cannons with your Corsair Jetbike squads. At BS 4, and with their Scout ability to outflank you can get rear/side armor shots galore
hope this helps a bit. I play the Corsair list quite a bit and would be happy to help with any questions if you need it.
Cheers,
ESE