Do you mean the piece that is between the head and the shaft? If so that is called the ferrule.
Do you mean Fujikura? If so, then yes, Fujikura make some of the best golf shafts in Golf.
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.
Do you mean when you are waiting to tee off? Then the answer is no, you don't have to but you can do. You can hold it by the shaft, or hold the grip with the head on the ground.
wedge
pitching wedge
The Loft
Angled
Fairway Wood
Frequency matched. Basically, the movements of the shaft ie backwards and forwards during impact are all the same.
Ask Dustin Johnson
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.