Some stuff I'd consider adding to a larger kit...

-Butterfly bandages or Steri-strips for larger wounds
-Trauma bandage or panty liners or gauze or handkerchief to control bleeding
-bottle of povidone iodine or a bunch of swabs
-alcohol swabs for general cleaning and tinder
-toothpick
-fresnel lens
-antidiarrhretic
-antihistamine
-decongestant
-nylon cord in addition to or in place of paracord
-plastic, nylon, or silnylon poncho in addition to or in place of space blanket
-butane lighter for redundancy and convenience
-consider using mirror-type compass in place of small compass and signal mirror
-set a limit on how many days the kit should support you, and include water tabs and meds only enough for that time
-if by water purification device you mean a filter, you might consider using a second chemical method like Aqua Mira or sublimated iodine crystals (smaller, less likely to fail)
-I like the Esbit stove (also purifies water by boiling) but you will need a metal pot. Maybe your kit container? Look at the MSR Stowaway pots. The handle latches the lid shut.
-take a sharpening stone you know you can use. I need a round stone, and a ceramic rod or diamond rod works well for me. Also the Spyderco ceramic files provide both round and flat and grooved surfaces.
-unwaxed, plain dental floss for hygeine and strong thread

Hope that helps some...

Bear