Yes, EPDM rubber roof bubbling and separation can often be repaired by cutting small slits in bubbles, removing trapped air/moisture, applying adhesive underneath, and sealing with appropriate sealant.
Soft spot near vent indicates water-damaged wood. Remove membrane, cut out damaged plywood, replace with marine-grade, reseal membrane. Fix the vent leak that caused it.
Aqua Hot engine hose failure requires coolant hose repair or temporary bypass to Aqua Hot. Carry spare heater hose, clamps, and coolant for roadside emergencies. Bypass Aqua Hot if needed to get to shop.