Eeprom should last > 100 000 write cycles, some papers says 1000 000, so why worry?
In 10 Years you can change the values 10000 times, at least.
But if you make changes at the program, the first thing that LDmicro do is reading the variables, so the rung must be always true at startup.
LCD, I made some time ago a program for you? forgotten?
http://cq.cx/ladder-forum.pl?action=viewthread&parent=3753