Do you mean Fujikura? If so, then yes, Fujikura make some of the best golf shafts in Golf.
Shaft is the handle of the golf club.
offset
it is a taylor made golf shaft that has a smaller dia at the bottom of the grip .
It means the shaft is flexed 4.26 inches from its original created spot. A person who gets this kind of shaft is someone who has a flatter golf swing.
No, a golf shaft will fit both right and left handed clubs.
Do you mean the piece that is between the head and the shaft? If so that is called the ferrule.
The number relates to the loft of the club and the length of the shaft. For example a 3 iron has the lowest loft and longest shaft. A 7 irons has more loft and a shorter shaft than the 3 iron.
Nothing it is a brand of shaft, the specs in all shafts differ
Hosel is the the socket (or neck) in the head of a golf club into which the shaft is inserted.
Reshaft it with the proper length shaft, you local golf shop or professional should be able to do it for you easily and cheaply.
Selecting the right shaft can make or break your game. If you are not using the shaft that is fitted for you, you could be hurting your game. For a detailed answer on how shafts work, you can go to the link below. I suggest you go to a golf professional and have them fit you for a shaft.