Mr. Premise said:
There's no need to refrigerate it because it gets better with age but how you store it depends on the climate where you're at. It probably tastes rougher because storing it in those kinds of bags might make it dry out. You can mist it with water to make it moist again. For long term storage, you want it to be "low case." "Case" refers to the amount of moisture in the leaf. Low case is not bone dry but one step above. It will not crumble into dust when crushed. Low case is ideal for storage. Medium case is ideal for smoking, kid of a leathery feel, won't break when crushed and, if shredded, it will be kind of spongy. If you squeeze it together it will spring back. High case is moist, if you press it together it can stay pressed, if not shredded it will feel moist. Storing in high case can lead to mold.
I use two methods for long term storage: Mason jars if the tobacco is already shredded and vapor-proof bags for whole leaf. If you store it in regular plastic bags, even ziploc storage bags, humidity will escape over time and it will end up bone dry. The vapor proof bags can be sealed with an iron on low heat. They are made of triple laminated poly nylon. Members of the Fair Trade Tobacco forum can order the bags here: _http://fairtradetobacco.com/threads/418-Vapor-Proof-Bags.
As for your seeds, tobacco seeds will last up to ten years or more, depending on how they are stored. I store mine in half pint mason jars with those little dessicant bag things in them. The dryer the better for storing seeds. At four years they should be fine. If you grow them on your balcony, just use 5 gallon pots and they will do fine.
And, yes, any tobacco you can smoke in cigarettes you can also smoke in a pipe.