If you're going to take a Jump Pack Canoness, you might as well make her good at something
. Either an Inferno Pistol for tankhunting or a Blessed Weapon for effective combat ability, or drop the Jump Pack and give her a Book oSL instead.
The Storm Bolter on the Exorcist is kind of pushing it.. you don't
want to be firing it if you have the option of firing the Exorcist. Even if you lose the weapon, you're probably going to be moving it anyway, from the back of your force to a contestable Table quarter or somesuch, rather than keeping it at a speed where a storm bolter would be usable.
You might want one
of your units to have Flamers, just to deal with Nids, Orks or Eldar [guardians]. With two melta squads and the Exorcist, you shouldn't have many tank hunting problems in only 1000 points.
Retributors are useless without a Squad Leader to let them use Faith. Perhaps if you put the Un-packed Canoness I suggested earlier in this unit it would be more usable.
EDIT: Oh, and faith is next to useless in your army, since none of your squads have faithful characters in them.
And in future, don't list specific points costs for models or wargear or anything, not even the cost of a basic sister. It's against GW's copyright rules, and could get our forum in some trouble.