On the Boeings that I have flown the check list is called; "Engine Fire, Severe damage or Separation" and is carried out as soon as possible after achieving/when at a safe height. In the case of a separation you are likely to get a Bleed Duct leak message and this will require prompt attention too.
A fuel imbalance checklist is a separate checklist and would be carried out when the fuel imbalance became obvious or EICAS messages called for it.
Normal policy is not to try and combine checklists, it is the Captains job to decide the priorities and call for the appropriate lists in due turn, each to be treated as a separate entity.
Hope this helps.