Building toward 1500

I'm building toward 1500, but this is what I've got so far:

GM
4 Terminators
Incinerator
344

Captain with Psycannon
5 Terminators
Psycannon
346

Grey Knights (4+ Justicar)
150

Grey Knights (4+ Justicar)
150

Dreadnought
Twin-Linked Lascannon
Missile Launcher
Extra Armour
145

Dreadnought
Assault Cannon
Missile Launcher
HK Missile
Extra Armour
140

1275

Everything's pretty naked at the moment and I have 225 free.
Is it worth taking Psychic powers on the terminators?
If I'm adding heavy weapons to the grey knight squads I want to be adding whole new troopers, otherwise their hand-to-hand abilities will drop to being negligible.

The second squad will be the closest thing I have to a line unit, chewing up infantry until its time to counter attack.
The GM's unit will hopefully make sure that counter attack kills enough to send the daemons/xenos/brightly coloured whusses running..
My opponents tend to be ok with me using the Assaultcannon with the modern rules. A lot of people see the HK as being a waste, but it's useful against transports. The dread can fire 2 krak missiles in the first turn and then switch to frag missiles and the assault cannon for taking out the infantry once the distance has closed a little.

All this depends very much on the enemy though, but I figure that the Grey Knights can adapt.

I like the fact that you have 2 hard hitting units w/ the GM+retinue and the GKT squad. However, you might be a little light on the PAGK troops units. 5 man units are not that resilient. For your remaining points, I'd probably add another squad and maybe bump them all up to at least 6-man squads. Investing in a special weapon or two is also not a bad idea.

As far as heavies, I'm more inclined to drop one of the dreads and add some more points to get a godhammer pattern LR. It'll provide one of your units some mobility plus give you some serious long range AT. But that's just me...I love LR's. I run 2 of them in a 1500 pt list

I agree with Rivan. Definitely have to beef-up the Troop choices first. There's been a few people that has had some success with an all foot-slogging list but LR's can make life a whole lot easier. Since you have the models already you might as well try out the hoof'n-it list to see if it works for you. The only psychic power I'd go for is Hammerhand for your GM and B-C.

I'd just bulk out your two PAGK squads.
Another squad can be useful for objectives, but I'd be more inclined to add some psycannons and lay down fire while your terminators advance

With two such termie squads and dreads to gaurd your PAGK I honestly might Deep strike the termies.

I mix up my lists alot, and I'm one of the people who's had alot of success with footslogging. I took a 1LR 1850 to a tourney today and won it. Due to the recent success of MSU i ran a bunch of 6 man PAGK squads with a special weapon (or two) in each. It worked out really well for me! Troops are important in 5th, so i'd say 3 is a MINIMUM for any army, and 4 is probably optimal. Smart use of cover and shrouding will usually see at least 1-2 through.

The Dual psycannon squad is a great objective holder, i rarely leave home without one! I usually take it as a 5 man and through an inquisitor with artificer armor and emperors Tarot back there for extra wound soaking goodness!

I like that you run dreads, but I think dreads should almost always have a CCW. any anti-troop fire should be from GK storm bolters/Psycannons, and I run my dreads CCW and either melta or las. even if they sit back firing, the enemy is afraid to get close, and using a s10 close combat weapon is better odds than any gun on poping vehicles! Plus you always take smoke on CCW dreads, and our smoke is one of the best things about GK (always glances!) run it in cover while smoked and it's nigh invulnerable, and then next turn it jumps out using melta or las goodness and assaulting things!

OK, so it's looking like another 5 knights and as many cannons and incinerators I can shoehorn in there. I can decide later whether to reinforce the units I have or create a new one, but I tend to prefer small squads as they're easier to control the enemy LOS to them which I find is especially important if that enemy has a battlecannon.

Rather than taking hammerhand, would it be worth swapping out a normal terminator for one with a thunderhammer and storm shield? I'm thinking he'd be useful for the grandmaster's squad if there're any eternal warrior types knocking around. If anyone's teleporting it will probably be the GM's squad to reinforce whichever PAGK is having a hard time. In most cases the captain's group will usually be needed for shooting people full of holes.

The next dreadnought I'm working on has shoulder mounted lascannons, an incinerator and a powerfist, so I might swap him in over the assault cannon if it's not tearing up enough vehicles.

I'm going to hold off on the landraiders until I get my intial 1500 sorted. I'm a big fan of them and used a couple in my space wolf army regularly back in third/fourth edition, but I often came across issues in dense terrain/cityfight games because it's a big model to drive about and it's sometimes difficult to get both sponsons on target at closer ranges. On the other hand they'd quite plainly be life savers on a more open field, so I'll see how it goes.

The crusader is fantastic in dense terrain because it gets cover saves untill it drives close enough to unlease it's awesome firepower, but I digress.

It's almost never a bad idea to have ONE guy with a thunderhammer in a decent sized termie squad - Their real strength is s6 power weapons at initiative, but we all make sacrifices for anti tank. However, I'd consider hammerhand AS WELL. It's almost an auto include on my HQ's because of the +1 attack and s8 on a model that already has a good number of attacks for very few points. Against vehicles this goes from "maybe i'll do something" to "most likely a few results", and did i mention it's cheap?

Makes sense.
I like my psychic powers how I like my women.
Cheap with most likely a result.

dude....thats wrong,for a mesely worm of the false Emperors lapdog.I mean even Nurgle respects women more.

I used to be a radical Inquisitor.
I'm getting therapy.