There's not really a reason for it. It removes nerves and makes sex less pleasurable for those who have had it done. It's mostly done because certain religions demand it.
There is nothing wrong with that.
Abraham. He was 99.
No. Circumcision has nothing to do with fertility.
Circumcised means that the man has had his foreskin removed. In Jewish males this normally happens about a week after birth, cicumcision can be carried out at any time though. There are instances where females can be circumcised but I don't know how that works!
About $4.000
Yes, if the first circumcision went wrong.
No, a man does not have to be circumcised in order to father a child.
Yes, yes it is.
Circumcision has nothing to do with catching diseases.
There is no Yiddish word that refers to a circumcised person. You would just say "a Man mit a Milah" (א מאן מיט א מילה), which means "a man with a circumcision"
If it was done without any complications then there would be a man with a penis that is less pleasurable to himself and to his pardner.
Yes, yes he does.