The swooping hawks can work, but only if you trim them down. You have an Autarch to boost reserve rolls, so they can yo yo effecitvely, and drop a bolter pie plate anywhere on the map every turn, while the enemy cannot shoot them
Take a minimum squad (4+ Exarch) and give the Exarch Skyleap only. That should be about 134 points. If you feel you must upgrade the exarch, the sunrifle is ok (but since you'll often rather leap than shoot, you'll only get one good volley out of it at the end of the game) and Intercept is decently cheap if you want to *try* to stop a tank. Otherwise, cheap and with an autarch.
note the autarch's 2 handed weapon does not replace his pistol, so don't worry about buying him a sweet weapon. Not a Las Blaster though! Give the man something good, like a fusion gun. Also if you are paying for mandiblasters, its a shame not to give him a powersword, so he can ignore armor saves. Also you can't take both mandiblasters and a banshee mask. pick one (blasters are generally better)
Dire Avengers are over built. Pick 1 power and stick with it. Also try to get them some wave serpents. Dire Avengers on foot are inferior to pathfinders and Guardian Jetbikes.
Crackshot is better on the reaper launcher, as it ignores cover, and lets you re roll wounds, for massive damage to marines. You sould also run the smallest Dark Reaper squad possible, as its really only the exarch who kills anything with cover what it is these days.
To keep the general theme of your list, I'd try something like this
(115) Autarch- Bike, Fusion Gun, Scorpion Chainsword
(90) Farseer- Guide, Warding
(210) 6 Gu Bikes + Warlock- 2 cannons, spear, destructor
(120) 5 Pathfinders
(60) 5 Dire Avengers
(139) 4 Swooping Hawks + Exarch- Skyleap, Intercept
(147) 2 Dark Reapers + Exarch- tempest launcher, crack shot
(147) 2 Dark Reapers + Exarch- tempest launcher, crack shot
(170) Falcon- holofields, eml
The Autarch rides with the Guardian Bikes, and hunts tanks or infantry, he has a chainsword... just because 5 points to make him s4 may be worth it.
Farseer and small avenger squad ride in the falcon, park on an objective, and shoot stuff.
Rangers do the same.
Reapers shoot at things, and the exarchs slaughter whole squads of enemy marines, in or out of cover.
Hawks bounce in and out dropping pie plates. They can try to haywire a tank in desperate times, but I wouldn't count on it.
The other option of course, is dropping your Autarch, hawks and reapers, then grabbing a farseer and mounting all your Avengers (2 squads in wave serpents, one 5 man in the falcon) That would give you a very standard and effective eldar list. Especially if you add fire dragons for some heavy anti tank.