1. If you bank left then let go or zero the stick the aircraft will stay at the angle of bank where you let go as long as it is inside the limits - above (45 degrees?) it needs the stick held over or it will roll back to 45 - will not let you bank more than 60 degrees.
2. No problem flying manually, there are differences but you will not notice them most of the time.
3. Your choice though you can only Autoland at fields that are cleared for it so it will depend on the routes you fly - charter you will probably only be able to autoland at just over 50% of the places you land - I normally just about manage 2-3 autolands between sim checks, but that is mainly my choice.
4. "LAW" is the flight control law that controls how the aircraft flies - much of which controls bank angle as in 1. and also what happens with pitch rate, and low and high speed handling.