Keeping it cheap at 1000 points is good. You may have been too cheap, though. This guy really ought to have meltabombs so he at least stands a chance against something with an armor value.
Power weapons are...silly. Hidden powerfists are markedly better. The plasma gun will prevent you from assaulting so should be replaced with a meltagun.
Unfortunatly, in my experience if you equip a unit with a powefist the enemy will simply remove models from base to base contact after your regular attacks so that the powerfist can't attack in the next initiative step, making the powerfist a useless item you pay alot for.(Powerfists are quite expensive to load up on in 1000 points. 1/10 of my army being pure powerfists doesn't sound right!) I want a plasma over melta for more ranged ap2. Plus, that unit is not meant purely for assault but rather to plant itself on an objective or other vantage point.(They will most likely get assaultED so I put a powersword with them.)
Oh, for amphetamine parrots and giggles i did some math hammer. Against MEQs, a marine with a powersword is roughly as cost-efficient as a marine with a powerfist. Against anything <T4(Tau, eldar, guard, sisters, etc.), the powersword is more cost-efficient. Really I'm only losing out against MC's/Vehicles. Powerswords are anything but silly IMO.
powerfists > power weapon and will let you drop the meltabombs here.
If I can fit one powerfist in it will be with the assault sgt. But where do I free up the points? I'll switch the melta bombs from vetsarge to chaplain but I don't see many area's where I can free up points with.
I think if you're going to be mobile this Predator is a bad choice. TL Las and Heavy Bolters will let this keep up with your Razorbacks.
Sure it would make the predator able to shoot more weapons on the move, but the roles of the weapons are completely different. I want the predator for tank/transport/creature busting. 2 lascannons>1 TL lascannon. Heavybolters wouldn't fit it's planned role in my army, They wouldn't be effective against most the targets I want to shoot at, and if i shoot at infantry, the lascannons are extremely inefficient.
The Whirlwind is also a curious choice for a mobile army. I've never been a fan, myself, as it seems like a waste of a perfectly good BS to drop ordnance like that. I knwo other people are big fans so I won't begrudge you the tank, if you like it.
Again, I am just tempted to try artillery thats actually feasible. Plus, BS doesnt matter when it's ordanance thats fairly cheap. My whole army doesn't need to be mobile, just a good portion of it. In fact there will be some games most of army will be hardly moving at all (AKA any game vs. nids/dark eldar/*insert pure close-combate army here*)
Thanks for the critique, you made me double-think the choices I made.