As Ford stated for #3 yes the 16i, 18i and 31i have this function along with pretty much any Fanuc that I have used.
In all 3 controls 16i, 18i, and 31i it is set by parameter 1401.1 (LPR). Which if set to 0 it will move the axis in a non-linear move or along each axis independently. If set to 1 it will move each axis as to create a straight line.
Stevo