Looks pretty good.
  My recommendations for possible ways to spend those remaining points:
  -Special Weapons squad attached to the HQ with a demo charge and Drop Troops
  -Give the Cannoness a jump pack and maybe a power weapon.  Run her attached to the seraphim.  Leave her behind if things get desperate and you have to hit and run when you'd normally prefer not to (so, declare her to be separating from the seraphim during any turn in which you are planning to assault with them).  She'll tie up whatever the seraphim jumped away from for another turn, and then most likely die, giving you the bonus faith.
  -The one non-drop troop platoon command squad: I'd take the plasma pistol away from the officer and either give the squad a heavy weapon or give him a power weapon and use him as a light counter-charge unit.
  -Make your HQ a true Heroic Senior Officer, and then give the non-drop troop Junior Officer the Honorifica, giving you a second sphere of bonus leadership.
  -Give the platoon command squad with the 4 meltas the sharpshooters doctrine.  Although, I'd be more inclined to use a third veteran squad for this job, as the BS4 is still better than BS3+sharpshooters.  
  Obviously, you can't do all of these things, but I thought I'd throw a few suggestions out there.