A few Questions if I may? I have tried searching, but probably not very well, and have not come up with the answers.

1 When first powered up (Marlin RC-8 BugFix) the X Y Z on the LCD alternately flashes ? ? ?, I assume this is an indication that homing has not taken place?
2 After homing X Y Z stay constant , again I assume an indication that the machine has been homed? If I go back a while later, X Y Z are flashing on and off. I am guessing that this is an indication that the steppers have been disabled and that calibration MAY have been lost?
3 Does G28 wipe out G29 data, i.e. after doing a G28 another G29 is required to repopulate the bed leveling data?
4 Does, or can, the G29 data be saved to EEPROM

Thanks,