couple of things
1 give that farseer doom & mind war. much better combo.
2 give the dragon's falcon a bright lance. you then have a completely dedicated vehicle that will take more than 1 turn to shoot down AND your enemy will concentrate all their fire on it!
3 switch the BL on the Avenger's Waveserpent to a ML. just more effective for their role.
4 the guardians MUST take a HVY wep platform unless they are storm guardians. i'd split it into 2 squads of 10 guardians with a warlock w/ conceal and give each a scatter laser (they count as assualt for the guardians. really, they do)
5 the swoopers are good, just make sure you use em right. and without an autarch it is very hard to do. i'd drop em for spiders in this list.
6 in this list i'd drop that wraithlord and get some dark reapers
really you will find they more than pay for themselves.