I’m sure Odo’s thought of countless scenarious where Rom - successfully or not - kills his brother for the bar
You know how Batman has come up with a plan to defeat every one of his Justice League friends in the event that they go rogue? Odo does that with imagining everyone he knows committing crimes. Every possible crime that each person would have means, motive and opportunity to commit, allowing for the psychology of the individual. He has EXTENSIVE files and in particular watches Keiko O'Brien closely.
1. Does he also keep a file with a countdown to the Chief’s next disappearance? Hmmm, been 5 months, the chief is due to be taken hostage, or go it alone or replaced by a replicant.
2. scenarious. idk where that came from