"Hello All, I would like to ask a question about the word LOVE which is used in the scores in ... like "love". Is this correct? And if so: why was this originally French word introduced into an originally British sport?"
Why do you think it's originally a British sport?
According to http://tennis.about.com/od/history/a/earlyhistory.htm it's probably of medieval French origin.
Lawn tennis, on the other hand, is of relatively recent origin - 1873 - and it is British. See here
"And also in connection with tennis: Is the term "DEUCE" connected with the French word "DEUX"?"
Yes - it means either side have to win two games in a row to win the set.
A simple Google search for the terms "tennis2 and "origins" would have found you those links and many others in a fraction of a second.
Regards, Einde O'Callaghan