ok, lets see where to begin
Baron is decent, he is for your beasts
The haemies are just there for pain tokens??? what about equipment like LGs??? or maybe a power axe (which actually makes them decent in combat)??? But lets see where we can free up some points.
Ah... here we go. Why 4 wracks??? If you are taking them for the venom, why not just take 3 and save 20 points??? well those 20 pts can easily go for 2 power axes or two LGs on your haemies...
The wyches, the bulk of your army. A decent build. Im not a fan of it but Ive seen it work. My question goes to why dissies? Your list lacks AT, and even though its only 2 DL, every one goes towards fixing that. Also I would drop the NS on them, and use those 20 points later. NS only really work when everything has NS, as with premeasuring now people can check to make sure if they can hit it, and then choose a new target.
May I ask why 7 Reavers??? you normally see groups of 3, 6, or 9, as those are the amounts you need for more special weapons. 7 just seems odd, and those 44 points can be used elsewhere. Also I am a fan of either AI reavers, or AT reavers, not mixing the special weapons. The reason being is when you arent shooting at tanks, your wasting those points spent on heat lances, but when you are shooting at tanks, your wasting the points spent on the caltrops. I find that the bladevane itself does decent at AI anyway, so there really isnt a reason to spend more points there than you had too.
Now the 2 razorwings are actually really interesting choice in this list, as you lack long range AI. The problem I see though is that they arent on the board T1, which means there are less things for your opponent to shoot at. While your normally like "thats a good thing right? as my razorwings will be safe" Its actually bad when a bulk of your points are built into wych raiders, as they are really fragile. Now Im not saying razorwings are a bad choice, but I would rather run 2 ravagers instead.
Now if you are dead set on razorwings, remember those 10 points I said hold onto from the nightshields? Our planes are begging for flickerfields. The reason why is when you dodge for a 5+ coversave, you can only snapfire the next round. That means no missles and dark lances only hitting on 6s. Flickerfields make it so you never have to dodge to get a save, which is amazing for 10 pts. I would buy them everytime for our planes.
Edit: The razorwings do have flickerfields... completely missed that