dchinell:
There is a small risk that the pills contaminate each other. But there are other advantages for separate bags:
- better managing (expiration date, supply, contents of bag)
- easier finding of the right pill
- no need to touch the pills you don´t need for the job at hand, that lowers the risk of contaminating them
- you considered the possibility that other people might use the kit, if they´re unfamiliar with the appearance of a pill they can easyly get the right one

For the fishing line you guess what size of fish you´re going to catch (be optimistic here). Add 20 - 50% to that weight. That would be a reasonable test strength for freshwater. Don´t go for less than 0.1" though. I have monofilament with 50 pounds strength in my kit.
It would be adviseable to find a fisherman who can show you how to catch a fish. Most fishermen - at least the ones I know - would teach you the basics if you show real interest. Learning it from a book is really the hard way.