by learning to speak french
No, speaking French is not a requirement to join the French Foreign Legion. However, recruits will be expected to learn French during their time in the Legion.
Unless you are French, you can only join the French Foreign Legion.
no they can not
As far as I know, you have to be in perfect health to join the French foreign legion. There is a thorough medical check during the selection process.
If they weren't a French citizen, their only option would be the Foreign Legion.
You cannot enlist with the French Foreign Legion from abroad. You have to travel to France, and to go through a selection process and selection tests. Terms and conditions are explained in link below (French Foreign Legion website - English version)
Gurkhas were amongst the toughest fighting men alive. Check with the Legion.
40
If you're a French citizen, you can join the French Army. If you are not a French citizen, you can join the Foreign Legion, but you will be enlisted as a single soldier regardless of your marital status.
yes
Not until military time in your unit is over
Around 1500 to date