Well, I'm a newbie too, so you can take this advice for what its worth:
Overall, too many points invested in each model. All the upgrades make them very expensive and, given the Eldar's fragile nature, you're running the risk of losing quite a lot of points due to one good roll.
Avatar - have heard mixed reviews and don't have one myself. Let me know your views.
Farseer - Too many Psyker abilities; I'd pick one or two and keep that. 40 points for spirit stones just seems like too much to me, but more experienced players may say otherwise.
Howling Banshees / Scorpions - You need way more of each, like full squads of ten. As it is now, with only 5 each, one volley could wipe them out before they even reach the front lines - strength in numbers, ya know.
Run those Scorp's in a Wave Serpent too because they're too slow to Fleet of Foot. These are some of your best troops, so max out. Drop Warshout on the Banshee Exarch and get Biting Blade / Crushing Blow for the Scorp leader instead of Scorp Claw.
Wraith Guard - Have heard good things and plan to get some myself. Putting them in a Wave Serpent is smart, though some may say they're tough enough to withstand a long march. I think the Wave Serpent gets them into the action faster, though, and is the right way to go. At 402 points, its expensive; drop the CTM because you don't want to be peek-a-boo attacking with this one - move max into enemy lines (or behind some cover if you can't make it) and then dump out the dead boys, whale away with twin-linked weapons and wraithcannons, rinse, repeat. Also drop the Star Engines for Vectored - drop down into cover to get the hull down cover and at least you can reroll failed terrain checks.
Guardian Defenders - Excellent choice taking the Grav Platform, but you may have better results with a Starcannon. Drop two of the defenders in favor of a Warlock w/Conceal. A 5+ cover save is a wonderful thing. Take another squad if you can.
Rangers - Don't use them; let me know your views.
Jetbike Squadron - Drop them to free up points for your Wave Serpent.
Vyper - Too many points invested here - especially for a gunner with BS3. Drop the CTM and Holo Field. Run this guy behind enemy lines and try to take out one or two tanks. If successful, he's been worth the points. As long as he's moved 6" or more, he only gets Glancing.
Dark Reapers - This is the next unit I need to buy. Heard they're devastating, so good choice.
Falcon - Again, too much going on here. I ran the same unit against IG, hid it behind a building, peeked out, fired, James Browned behind the building (Jump back - kiss myself!) and pecked away at his Heavy Support.
However, I could only shoot one dang weapon a turn, so the second (expensive) weapon really didn't come into play (and is only really useful if I lost the first one).
Because I like to keep my tanks moving for the Glance, I think its a better investment to go for Serpent (twin linked).
Fire Prism - Thought this was very cool until I learned more about the Wraithlord. It can't carry troops, has a low BS of 3 and would be a pain to guide with a Farseer.
Not quite as cool to me now, I'd drop in order to build up your Banshees / Scorps.
Well, thats it. Again, there are more veteran players on here that can give you more sound advice, but I hope I helped.
Mecha T
