I think if you made the chaplain a master of sanctity you wouldnt regret it. You can drop the 6th marine from the lascannon squad to get the points.
For someone who doesnt like tanks you are pretty lenient, though I have been with less anti tank in 1500 pts before with marines. What you have is enough.
You should definately plan on deep striking those terminators. Starting them out on the field, in my opinion, doesnt work. They will march up, get shot, and it is very easy to run from them. Thanks to the assault cannons, people will be shooting at them a lot.
Though I am trying to decide if, in a 1500 pt game, they would shrug off the shots ur opponent has to direct at them....