Attitude hold and control stick steering are not techniques that airbus is using, but the name given to AP on other aircraft that accomplish the same thing.
Take you hand off the stick, feet on the floor. What are you commanding on the 320? No input? No, you are commanding 0 pitch rate, 0 roll rate, and 0 yaw rate. Any external forces (wind) that provide something other than zero, the FBW system will try to counteract. But, if the aircraft ends up in a 10 deg bank, the FBW does not roll the aircraft back to zero. In smooth air, it effectively holds whatever pitch and roll angle that you set.
Side sticks not connected. No problem if your flying partner has 8K hours. Sometimes a problem with low time pilots. If both sticks are moved at the same time you get a "dual input" oral warning, but the command of both sticks are "added" together. Both sticks have a little red button that locks out the other stick. Two uses for the button. If a stick is defective and puts in a bad input, you can take priority ("Priority left") and takeover. Hold the button for 42 seconds and the other stick is locked out for the remainder of the flight.
I wish the sticks were connected, I wish the throttles moved, and I wish Boeing could put a table in the cockpit so I don't have to eat on my thighs