Thanks for playing Lost Eons! Yes, coming from an FKR mindset I wanted to leave the exact meanings of the conditions to the GM, as they will best understand the situation at hand. But my rulings in general would be-
Grappled- Can’t move until use an action to free themselves in test of Muscle vs Opponent, Soul Dice becomes d4 while grappled.
Blinded- Counts as Dazed Condition, so Soul Dice becomes d4, disadvantage on actions that require sight.
Disarmed- lose weapon and any benefits, any attacks and defense rolls are at disadvantage.
As I say, these are rulings I would use in general, but they could differ in the moment. I hope that answers your question.