+1 on most of that
Replace the battery with an AGM and get a second key from the dealer plus make sure that the drivers door manual key operation is good, best way would be to replace the actuator shaft thingy that breaks or at least lube it well in any case and you have all the bases covered. I have never heard of anybody losing EWS synch when replacing battery, I think it only happens if the voltage is low for long enough for one module to loose the code and not the other.