Re: i may begin fly fishing... questions and advice?
Tippet is simply the final section of your leader. When you buy a tapered leader from the fly shop, say in 2x size (which is 7.1lb test), the 7.1lb section at the end (usually a few feet on a 9ft leader, based on the formula used to construct the leader) is the tippet. However, whereas a leader will last a long time, the tippet end will continue to get smaller as you tie on flies, snag up, break off fish, etc. In this case, you will replace the end with "tippet". Tippet is not one specific material: you can have fluorocarbon tippet, nylon tippet, you can use monofilament fishing line, even wire (a so-called "bite" tippet). These are available in all different sizes, and are usually given an X rating which corresponds to their breaking strength (in the example from before, 2x is 7.1lb test, while 5x is ~3lb test). Each has their own use, all of which you will eventually figure out but I can give a basic breakdown if you're not fully confused yet....
Fluoro: more abrasion resistant, neutrally buoyant (so sinks more than nylon), refraction index is closer to that of water (so theoretically its less visible to the fish)
Nylon: flexes better than fluoro, cheaper, floats (so it's great for fishing dry flies)
You will still catch fish with nylon, you don't HAVE to buy the expensive stuff.
IAFlyguy/Jason explained the bite tippet well, so I won't go into that one.
As you get more into fly fishing you will certainly develop ideas about what sort of tippet you like and when to use different sizes, but your best bet is to just talk to your local fly shop and see what they use.
Most importantly, I live in Buffalo, NY but would really like to take a trip to the Allegheny. I would be happy to bring extra gear and share the little I know about fly fishing, it really is a great hobby (well, make that obsession, I basically need a twelve-step program...).
Hope to see you on the water soon!
Oh, and you can absolutely chuck bait with a fly rod. I've heard fairly prominent people in the fly fishing world suggest that the best way to learn to get a drag-free drift for your flies is to start out fishing with worms. And rumor has it you can absolutely overhead cast a shrimp on a bare-hook in saltwater...
EDIT: Line wt is a (mostly) set system around which rod "weights" are designed. Your guess is right on about the 8wt line/rod for carp and such. And that 8wt line would be paired with an 8wt rod usually, since this would (again, usually) be the easiest to cast said line with. You should not have to worry about the breaking strength of the fly line itself, usually something will fail in front of your fly line. If not, fly fishing is going to get really expensive really fast, especially on the bigger wts. With 30 pounds of pull (which is actually a lot of work, try deadlifting a 30lb weight with a strong stick and heavy mono like you were fighting a fish...), you're liable to explode your rod, rather than just your line.
Working out a way to convince my university to allow me to hold my TA office hours on the nearby creek...