Camille,
You may want to specify max and min angles of propagation if you have a good idea of what they are, but that's not a must.
If you want to run a number of directions different from the default 5 (if that was also the default in V6P1), then yes, you need to specify that in your steering file.
Some keywords may be different in V7P2. Your princi file will have evolved also a bit, but there are also improvements and new features.
Noémie