With a list like this smoke launchers are you're friend, as is extra armour. And for 8 points to add both to each landraider, I can't see a good reason not too. With the machine spirit that means you can always move and fire one weapon, ad splitting targets when your stationary is what you need with so few units.
I'd ditch the Crusader, too much of a one trick pony. The Godhammer Landraider gives you another 24" of engagement range (which helps when staying away from melta weapons and lances). It isn't that amazing at killing infantry and if anything is only going to ensure you're Terminators and commander obliterate anything they assault, leaving them in the cold open afterwards. I feel the crusaders shape limits what it can really pour its shots into. **
For 1500 I would suggest leaving the Terminators at home and bringing another 6 man GK squad (5 + Justicar is my preference), but thats me.
Losing a Landraider in this list will hurt, as it does revolve around them. I understand the reasoning your using but a board isn't as big as everyone thinks, moving away is a lot of the time, harder than most people think.
As a side note, with GK you might want to consider mounting the lascannons on the front two slots rather than the rear. It gives you a couple of extra inches and a better firing arc on your front. Your squads are small enough you can disembark just out of one of the side doors without the extended front space. Handy for making a backdoor escape too.