You can ad a very small zip tie around the activation lever as well, to prevent leaks from that source (not that you'd have fluid all over, but it would be unpleasant to need it but the fuel had evaporated).

I'd second some water storage (gerber bags or MRE hot beverage bags, or oven bags) and possible a purifier. Also the needle and thread - very handy.

Great kit - well thought out for your needs.