I've been fiddling with a Dark Angels army list myself.
Are you planning to walk or Deep Strike in? If you want to Deep Strike (which I'd say are the Deathwing's main thing) then I'd try and work in a Teleport Homer somewhere. That would involve removing either the Dreadnought or a couple of Land Speeders and getting a nice basic Ravenwing Squad. This way at least you know you have a good chance of deep striking a Deathwing Squad onto an objective early on in the game, or else in a significant part of the Battlefield or launching an early assault upon a weak point in your enemy's line.
1,000pts is tricky when you use Terminators as Troops as you know all they need to do is kill 3 in each squad to draw most games
I think you've gone for a sensible approach with the Deathwing Squads, being able to engage all kinds, but the danger will always be that those equipped without Storm Shields will be susceptible to Plasma, Melta, Power Weapons, Rending etc. Personally I'd drop the chainfists. It's unlikely you'll meet an AV14 vehicle in a thousand points and you already have 3 Multi-meltas/Typhoons & 2 Cyclones for anti-tank, not to mention the Dreads Plasma Cannon for transports as well. Drop the chainfists and give them
TH/
SS as your main concern will be objective camping, survival and counter attack tactics. If you can squeeze it in I'd go for a Missile Launcher on the Dread as well, it's my favourite loadout at the moment
If you're worried about Infantry Hordes then give the Terminators Heavy Flamers instead.
That said I think you have enough firepower/staying power to cause most small armies problems.