That looks like a kit that has been assembled from experience. I think that you should replace the purification tablet set with MP1's. No aftertaste and they are the most effective presently on the market. I also think that you should add a pocket chainsaw, a Swedish firestick and a small compass. The leatherman is a good tool but it needs to be augmented with a Victorinox. One of the one handed models. The two compliment each other to a degree that has to be tried to be appreciated.
I think that my biggest concern would to be picking items that I can disperse about my person. On the assumption that I may be separated from my webbing.