Whether the FBI has anything on BU (e.g., leads, etc.) nobody currently knows. What we do know, is that BU has NOT been currently implicated in any official documents. As this case progresses, there is the possibility that the defendants accuse/bring down other associates and coaches in exchange for more lenient treatment. So BU may or may not have some personal criminal exposure.
Now, the UI has no criminal exposure. These events took place in previous years, so unless new information comes up that UI/Coaches are currently involved in fraud/crime, there is no concern. To be honest, even if coaches (at whatever school) were still involved in fraud/crime, that activity will likely cease/subside as a result of the FBI investigation in the next months.
As far as the NCAA, even if the rule of head coaching responsibility gets applied, there is still no UI exposure based on the fact that these crimes/inappropriateness were conducted not at UI, but while at OSU, SoCarolina, etc. The worst that can happen for UI, even in the case that penalties (criminal or NCAA) are brought up against BU, is that UI will have to fire him, which will set us back.
But unless things get uncovered on previous UI coaches, or current coaches at UI, the school has no criminal or NCAA exposure.