I agree. The LED will probably be the most current draining component on the board, while it's on.
Any wireless stuff will have greater battery life with LED's disabled completely.
Chime > 0 > Reset. Will disable chime feature.
If you haven't had your alarm serviced in a while, I think it would be a good idea.
The alarm panel shouldn't change any programming (switch chime on), if you have a power cut.