1)I was considering just a wetsuit, but what if the something happened in those coooold Alaska waters? Do you still think a wetsuit would be suitable?
Yeah, I believe that is what they used for artic diving, too.
2) As far as everything getting wet....will things in dry bags even get wet?? I was gonna have dry bags for food, clothes, sleeping bag, tent, all that good stuff...will it still all get wet? I have a small dry bag formy digital camera I was planning on bringing...should I be worried that my camera will get wet?
Sealline bags are good. But the trouble comes in when things get damp. Then in the holds, they get cold and condense. A wet tent will stay wet. Wet cloths will stay wet. Sleeping bags, ditto. One of the few times I can say a synthetic may work better. Tripple bagged, your food should be OK. But, do not open a bag unless you need to. Rain & drizzle, weak sunlight, cold weather makes for poor drying conditions. A good cotton cloth is fairly easy to dry out over some heat...like from your cooking stove. I set it over the top. It makes a good cleaning cloth for the camera. Get a good water resistant camera too. http://cascadedesigns.com/sealline/dry-sacks/nimbus-sack/product is a fair compromise between weight and extreme waterproofness.
3) Generally, no, you cannot pump salt water. While it is true that military grade filters can, this is NOT true for light duty hand helds. Insure you pump enough for at least your intended paddle time, and maybe a liter or two more.
4) I like the NRS brand, but it really doesn't matter. I tried a couple different types and pretty much gave up on special duty super dry stuff. My hands get wet. Skin gets soft. Blisters are the result after paddling 8-10 hours... Any paddling glove will help reduce pressure on your hands.