Those seams on the JP are a real distraction. I would recommend filing those asap. The best plastic fiiler I have used that I really like is actually 3M Red Spot Putty, you can pick it up at most any auto-parts store, it comes in a red and black tube, it is basically bondo that does not need to be mixed. Get those seems filled and I think that will be a big step toward a nice improvement.
Chaplains need chains. The best source for chain is scale model boat rigging, most well stocked hobby stores should have it, if not then you can find it online google-ing scale model anchor chain. Then you can wrap chain all over the place and that will help a lot.
As others have mentioned, those skull on top of the pack just don't look right. Check the bits supplier websites for chaos stuff, I am sure you will find a nice skull part that you can use that will "fit in" with the rest of the mod.
Lastly the helmet and lack of cape/cloak/tabbard is somewhat bothersome. Take a look at the chaplain conversion I did for my IF army;
View attachment 8443
Adding those draped elements really ads to the bad-ass-ness of a model.
Other than those things I think you are off to a great start!!
Ashton