Welcome
The 14 tooth sprocket is a very quick and easy improvement on the bike, you won't need to shorten the chain unless its very stretched, in which case, change it along with the rear sprocket !
If you do change the sprocket, make sure you adjust the chain correctly and turn the rear hub the correct direction to adjust the chain, otherwise you handling will go south very quickly !!
Other mods as stated are endless, limited only by your wallet to be honest.
Personally the best mod I have done to my bike other than the 14 tooth fron sprocket is to have a slipper clutch fitted and a power commander fitted and setup correctly, the bike is completely standard other than that now and is briliant. Mine used to be tricked up with most of the extras on it, but I've put it back to near standard now and still love it and I have some extra cash in my pocket now !!
Enjoy it..............
[Edited on 8-2-2004 by muttsnuts]