Okay I swear we're actually going to finish a run of this game this time I swear.
The following units cannot be killed off at all and must be used as much as they possibly can:
Sophia:
David:
Glaceon Mage:
Dual Dragons:
Safe units are the main team and will try to be used the most and have to be deployed when possible.
Other units may only be used if: -They are forced, like Roy, or Fa(e), as she is needed for the final chapter. -There is room for filler. -A recruitment is needed to recruit a character later: Lalum/Elphin cannot die because they are needed to recruit Percival. -A gaiden is needed: Sophia cannot die in her recruitment chapter because she is needed to obtain 14x.
Glac said she would start, so she should update soonish, hopefully.