Agreed on Optionlock. The plagues themselves tick down the list of things the Egyptians can suffer before relenting.
Driver is Action. Encounters, plagues, miracles, interventions -- all the tough decisions are in response to these, right from the get go (Pharoah wonders what he's going to do with his reckless sons after they bash up the Sphinx, Moses decides to leave Egypt after discovering his ancestry and killing the slave-driver).
Problem-Solving Style? I think this scene kind of teases out Moses' and Ramses' different styles:
Moses tackles things in a direct chain. "Do you not understand what Seti was?" If there's a wrong, it must be righted.
Ramses tries to balance things. The greatness of Egypt balances out the slavery. His father's legacy balances out his harshness and cruelty. I also think it's telling that Ramses' response to Moses' first direct challenge is one of sadness, rather than anger:
MOSES: I can no longer hide in the desert while they suffer...at your hands.
RAMSES (sadly): So you have returned, only to free them.