A: To refresh, FBI Raid says:

Select a doomed Keeper or Creeper currently on the table and discard it. If you have the Federal Agents on the table, you may discard any Keeper.

This means that if you have the Feds on the table in front of you when you play FBI Raid, you can discard any Keeper, regardless of whether it has doom or not. Without the Federal Agents, you could only discard a Keeper if it is doomed. (Note that all Creepers have doom, so nothing changes about that, you could always choose to discard a Creeper instead, whether you have the Feds or not).