I'd say negative on ziplock bags-You can get some nice drybags that wont break the bank at academy sports. If you believe ziplock bags will work you haven't been out in real foul conditions, I'd acquire a couple more mags instead of carrying a box of ammo-less bulk. I'd take the tomahawk with handle attached. If you need it for breaching you probably wont have time to stop and make one. Filters good but I'd bring water as well. Is it a good first aid kit with a compression bandage, ace wrap and a TQ?