Avoir les touches "Début" et "Fin", correctement mappée sur MacOS.

You could remap home and end by creating ~/Library/KeyBindings/ and saving a property list like this as DefaultKeyBinding.dict:

{
"\UF729" = moveToBeginningOfLine:; // home
"\UF72B" = moveToEndOfLine:; // end
"$\UF729" = moveToBeginningOfLineAndModifySelection:; // shift-home
"$\UF72B" = moveToEndOfLineAndModifySelection:; // shift-end
}

Most of the keybindings for editing text in OS X are defined in /System/Library/Frameworks/AppKit.framework/Resources/StandardKeyBinding.dict.